The Bohrok Va are the secondary monsters of the Bohrok archetype, lending different kinds of support to the primary Level 4 Flip Monsters. They themselves all come in the form of Level 2 Tuners with the ability to Special Summon themselves from the hand if you control their respective breed of Bohrok, making them the main means of access to the archetype’s own Synchro bosses, the Bahrag.
In addition to the shared traits above, all Bohrok Va have a helpful effect on the field and another one that activates during the End Phase of the turn in which they were sent from the field to the GY. The former is different for each monster, the latter divides them into two distinct flavours.
One of those are the Bohrok Va that use the End Phase to return a banished Krana to your hand, where it can lend its powers to the swarms once again.
The Tahnok Va, speedy and reckless, can pump its Level to 4 or 6 by banishing a Bohrok from among the top 3 cards of your Deck, but this might backfire if you fail to find one there. Should you succeed, though, you will instantly be able to pull out a nice and big Synchro in most cases, so it’s worth the risk. The Pahrak Va, known to be slow unless they have a reason to move quickly, will stack the top of your deck with a Bohrok card from the GY, which is an effect that goes from slow to fast depending on whether or not you have some way to draw a card. The noisy Lehvak Va drown out not only other sounds, but also your opponent’s Spells/Traps, though only with the backup of another Bohrok and at the cost of tributing itself. Would be a bit unfair otherwise.
The other flavour of Bohrok Va are those which grant you a draw in exchange for shuffling Bohrok from the GY into the Deck during the End Phase, which is a particularly valuable ability when things aren’t going too well for your strategy.
The Gahlok Va move slowly, yet steadily, and will attempt to add an extra Bohrok card from the top of your Deck to your hand once per turn. The Nuhvok Va take a more straightforward approach and just dig into the Deck at the appropriate cost of losing a card from your hand. Finally, the Kohrak Va are masters of evading attacks through camouflage, which lets them help you avoid battle. Not an amazing effect in the face of, you know, the entire concept of removal effects, but occasionally it does something.
With these monsters and the main Level 4 Bohrok in mind, the true power of the already good search spell Beware the Swarm becomes apparent. By adding either a Bohrok or Bohrok Va whose matching counterpart is in the GY, you instantly become able to place both of those monsters on the field. Assuming your hand is in a good enough state to not have to shuffle either of them back and you still have your Normal Summon, of course.
Like the larger Bohrok, the Bohrok Va also have the ability to form Kaita. These combiner models never played any role in the story at all, so I just went the route of giving them extra useful ways to support the archetype. And I’ll leave going over the dedicated fusion spell to the main Bohrok article, because most of the time you’d probably just Instant Fusion these guys out anyway.
Just like the regular Bohrok Va, both of the Kaita are Level 2 Tuners (their Level remains the same when combining simply because it’s more convenient for Synchro math this way), but being just a Spell Card away in any arbitrary deck means they need the restriction of only performing Synchro Summons with other Bohrok. Both also share the ability to replace themselves with another Bohrok Fusion (including the big ones) during the Standby Phase, but only if they were properly Fusion Summoned themselves, and Instant Fusion’s little clause doesn’t help here because in that case they won’t even live to the Standby Phase.
Their other effects activate during the End Phase of the turn they went from the field to the GY, be it because they were used as Synchro Material, tributed by their own effects, or otherwise destroyed. In the case of Bohrok Va Kaita Ja, this allows you to add any part of the swarms, Bohrok or Krana, from the Deck to your hand. Bohrok Va Kaita Za on the other hand Special Summons any Bohrok monster, regardless of Level, from the GY in face-down Defense Position.
Bohrok Va supplement the basic Bohrok strategy by aiding the circulation of resources and simplifying access to more powerful boss monsters. Since they require specific Bohrok names on the field to work to their full potential, they are best when used together with a smaller subset of the six breeds, which seems like the most reasonable way to play Bohrok anyway.
Examples of incorporating Bohrok Va like this can be found in any of the Bohrok decks of the BBTS release.