Theme Guide: Onu-Koro (BCOT)

Onu-Koro, Village of Earth

Field Spell

You can target up to 5 EARTH monsters in your GY; shuffle them into the Deck, then gain 600 LP for each card shuffled into the Main Deck this way. If your LP are higher than your opponent’s: You can send 1 EARTH monster from your hand or field to the GY, then pay LP in multiples of 1000 (max. 3000); draw 1 card for every 1000 LP paid, then, if your LP are lower than your opponent’s, send that many cards from your hand to the GY. You cannot Normal or Special Summon monsters the turn you activate this effect, except EARTH monsters. You can only use each effect of “Onu-Koro, Village of Earth” once per turn.

Bionicle: Coming of the Toa (v3.21.6)

In the underground caverns of Onu-Koro, hard work is rewarded with great wealth, at least according to the Principle of Prosperity. For the effects of the Field Spell, I interpreted “hard work” as “putting monsters in the GY”, which is usually a pretty decent indication you’re doing things, and “wealth” as the resources of both LP and cards. So the first effect trades the proof of your work, the monsters in the GY, for wealth in the form of LP, and the second directly trades that amassed wealth for cards.

There are several extra balancing factors to the draw effect, given that it can potentially draw up to 3. First, it only works when you have higher LP, so you have to do some healing and/or damage before using it. Second, you need to send an EARTH monster from your hand or field to the GY, mainly to downgrade the level of advantage you get and to make the effect a bit more conditional, but also as setup for LP regeneration. Third, if you pay so much that you are now behind in LP, you lose an equal number of cards to what you drew, which technically works out to a -1 but is still fairly good since you can freely put anything from your hand into the GY. Fourth, it locks you into only summoning EARTH monsters for the whole turn, just to be extra sure it doesn’t get randomly abused. A proper Onu-Koro deck is mostly okay with this restriction anyway.

It follows that, as an Onu-Koro player, you want to establish a stable loop of putting EARTH monsters in the GY while building your board, shuffling them back to gain LP, and potentially drawing additional cards to further strengthen your position. Now we’ll take a look at how other cards contribute towards that goal.

Turaga Whenua

Link Effect MonsterLink-2 [▼ ▶] | EARTH Spellcaster | ATK 1450

2 monsters, including an EARTH Warrior monster
Each time an EARTH monster(s) is sent from your hand or field to the GY, gain 400 LP for each. If this card is Link Summoned: You can pay 1000 LP; add 1 Level 4 or lower EARTH Warrior monster from your Deck to your hand, with a different name from the cards in your GY. You can only use this effect of “Turaga Whenua” once per turn.

Bionicle: Coming of the Toa (v3.21.6)

Noble Kanohi Ruru

Equip Spell

If another “Kanohi” card becomes equipped to the equipped monster, destroy this card. You can only use each of the following effects of “Noble Kanohi Ruru” once per turn.
●While this card is equipped to a “Turaga”, “Toa”, or “Makuta” monster: You can target 1 Set card your opponent controls; reveal it. If it is a Spell/Trap, inflict 500 damage to your opponent. If it is a monster with less ATK than the equipped monster, inflict damage to your opponent equal to the difference.
●If this card is in your GY: You can Tribute 1 monster, then target 1 “Turaga Whenua” in your GY; Special Summon it and equip it with this card.

Bionicle: Coming of the Toa (v3.21.6)

Whenua essentially acts as an overseer of the “work” you perform, providing small rewards in real time for every EARTH monster you put into the GY. On summon, he also helps you solve your current problems by learning from the mistakes of the past, or in non-lore terms, searches a low-level EARTH Warrior that isn’t in your GY yet. Of course, putting stuff back with Onu-Koro expands your search range here.

The Kanohi Ruru, Mask of Night Vision, doesn’t really have a main focus that synergizes with the Onu-Koro deck much – it just reveals Set cards, because that’s the mechanic that historically fits night vision best (for the record, hand reveals would be mind reading). It does also inflict some damage as a bonus, which could at least help achieve the necessary LP difference to use Onu-Koro to its full potential.

The search effect on Whenua is of course meant to fetch Onu-Matoran, and for that we have a few options.

C.C. Matoran Taipu

Effect MonsterLevel 2 | EARTH Warrior | ATK 1000 / DEF 500

You can Special Summon this card (from your hand), but you cannot declare an attack for the rest of this turn, except with “C.C. Matoran” monsters. You can only Special Summon “C.C. Matoran Taipu” once per turn this way. If this card is sent from the field to the GY: You can target 1 monster you control with less than 2000 ATK; it gains 1000 ATK/DEF until the end of the next turn.

Bionicle: Coming of the Toa (v3.21.6)

Matoran Tender Midak

Effect MonsterLevel 2 | EARTH Warrior | ATK 500 / DEF 500

If you control a “Matoran” monster, except “Matoran Tender Midak”: You can send this card from your hand to the GY; send 1 EARTH monster from your Deck to the GY, and if you do, gain 400 LP. If this card in your GY would be returned to the Deck by a card effect, you can add it to your hand instead. You can only use each effect of “Matoran Tender Midak” once per turn.

Bionicle: Coming of the Toa (v3.21.6)

Matoran Racer Onepu

Effect MonsterLevel 2 | EARTH Warrior | ATK 700 / DEF 500

When this card is Normal Summoned: You can target 1 of your banished EARTH monsters; place it on the bottom of the Deck, then you can reveal any number of “Matoran” monsters in your hand, and if you do, gain 500 LP for each. During your Main Phase: You can Special Summon 1 Level 4 or lower Beast “Rahi” monster from your hand or GY, but banish it when it leaves the field. You can only use each effect of “Matoran Racer Onepu” once per turn.

Bionicle: Challenge of the Rahi (v3.20.4)

Taipu is most importantly a free Special Summon from the hand, assuming it is either turn 1 or Main Phase 2 – otherwise there’s an attack restriction that can trip you up sometimes, fitting for a somewhat clumsy Matoran who is always eager to help. Aside from these attributes, Taipu is also notable for his unusual physical strength, reflected in his unusually high ATK stat which matches the stat boost he gives another small monster when sent from field to GY. You can also use that for chain blocking.

Midak, the eccentric Onu-Matoran who likes sunlight and spends his time in a hut full of Ussals on the surface, is the first half of a little engine that takes advantage of the deck’s built in resource cycling. His role is sending an EARTH monster from your Deck to the GY (yes, can be anything, hence the restriction to needing a Matoran on the field) for setup and some immediate LP gain, and later returning directly to your hand when he would be shuffled back by Onu-Koro, because the Deck is too dark for his tastes.

The second half of the combo is Onepu, the proud champion of the Ussal races. Having such a defining relationship with the crab Rahi, he actually interacts directly with it by Summoning it (or any other low-level Beast Rahi) from the GY. On Normal Summon, he can put a banished EARTH monster (such as an Ussal used in a previous iteration) back into your Deck and be rewarded with LP gain proportional to the size of his audience in your hand. So what exactly is the combo I’m talking about here? Well, the one missing key point is that the Ussal, a Level 4 EARTH Beast member of the Rahi archetype, can bring back another Level 4 or lower EARTH Beast monster from the GY when sent there.

Ussal, Crab Rahi

Pendulum Effect MonsterLevel 3 | Scale 2/2 | EARTH Beast | ATK 1000 / DEF 1000

Pendulum Scale = 2
[ Pendulum Effect ]
Once per turn: You can reduce the Pendulum Scale of the card in your other Pendulum Zone by 1 until the End Phase; this turn, while this card is in your Pendulum Zone, you can also Pendulum Summon “Rahi” Pendulum Monsters from your GY, but monsters Summoned this way are destroyed during the End Phase.
[ Monster Effect ]
If this card is sent to the GY: You can Special Summon 1 Level 4 or lower EARTH monster from your GY, except this card. If this card is banished: You can Special Summon 1 Level 3 or lower “Rahi” monster from your GY. You can only use 1 “Ussal, Crab Rahi” effect per turn, and only once that turn.

Bionicle: Challenge of the Rahi (v3.15.5)

What you do is this: Put Onepu on the field, activate Midak in your hand to send himself and an Ussal from the Deck to the GY, the Ussal triggers to bring back Midak, and with Onepu bringing back the Ussal you now have 3 monsters on the field. Do whatever combos you so desire from here, and once you’re done use Onu-Koro to shuffle back a bunch of EARTH monsters, including Midak who will instead come to your hand. Then on a subsequent turn you just need to find Onepu again, and due to him putting back the banished Ussal on Normal Summon everything is ready to go for another round.

A potential hole in our whole strategy of continuously shuffling monsters from the GY back to heal and draw is that we will eventually run out of Spells and Traps, as those are not recycled. It may not matter a lot of the time, but still, to our rescue comes the wise Toa of Earth.

Toa Mata Onua

Effect MonsterLevel 6 | EARTH Warrior | ATK 2100 / DEF 2100

To Tribute Summon this card face-up, you can Tribute an EARTH or “Toa Mata” monster in your hand, except “Toa Mata Onua”, instead of a monster you control. Once per turn, if a monster(s) is sent from the hand or Deck to the GY: You can target 1 card in either GY; place it on the top or bottom of the Deck, and if it was a monster whose original ATK in the GY was lower than this card’s current ATK, gain LP equal to the difference.

Bionicle: Coming of the Toa (v3.21.6)

Great Kanohi Pakari

Equip Spell

If another “Kanohi” card becomes equipped to the equipped monster, destroy this card. If the equipped monster is a “Toa” or “Makuta” monster, it gains 1000 ATK, also if it attacks a Defense Position monster, inflict piercing battle damage. If this card is sent to the GY: You can banish 1 monster from your GY; add 1 “Toa Mata Onua” from your Deck to your hand. You can only use this effect of “Great Kanohi Pakari” once per turn.

Bionicle: Coming of the Toa (v3.21.6)

Indeed, Onua gives us the ability to return any card from the GY to the Deck, assuming the trigger of a monster being sent from hand or Deck to GY applies. And beyond simple recycling, he comes with the benefits of working on both GYs, being able to place the card either on top or bottom of the Deck, and healing you if you return a monster with lower ATK than him. This means he can put your own Spells/Traps just a draw away, place something dead on top of the opponent’s Deck, take something they just sent to the GY away before it can be used, or simply be used for LP regeneration to enable Onu-Koro.

The Kanohi Pakari, Great Mask of Strength, also plays into these LP games. The bonus ATK on Onua makes it so you stand to gain more LP from his effect, and a high-ATK piercer is a pretty reliable way to damage your opponent and help establish the desired LP difference.

Sample Deck

Our goal is to do “work” – putting monsters from hand or field into the GY – as quickly as possible to get our LP and card advantage engine fueled, so this is basically a Link spam deck. In addition to our core engine of Taipu/Onepu/Midak/Ussal, the stars of this deck are the Goukis, which allow us to just keep throwing monsters onto the field while also refilling the hand with their own floating effects, supplementing the draws we get from Onu-Koro later in the game. Visiting the village are the Chronicler Takua and Po-Koro‘s Hafu, which together form yet another way to get out a total of up to three monsters off one card (though banishing the one Hafu summons is a little detrimental to our resource loop).

The ultimate payoffs going first are usually some combination of Knightmare Gryphon, Apollousa, and Tri-Gate Wizard, while going second the big power play is obviously Accesscode. Grandsoil is both a main deck boss and a combo piece that is very easy to use in this strategy, since you can easily control the number of EARTH monsters in your GY.

Best of Test

Best of Test: Onu-Koro


The greatest strength of Onu-Koro decks is the ability to replenish resources, both cards and LP, over and over again. Even if you can’t kill your opponent quickly, you can probably survive long enough to outlast them if things go reasonably well, though most of the time there isn’t a need to drag things out too much.

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