If you control no other cards and have at least 1 other card in your hand: Shuffle all Beast-Warrior-Type "Bujin" monsters from your Graveyard into the Deck (min. 1), and if you do, send your entire hand to the Graveyard (min. 1), then you can add up to 3 Beast-Warrior-Type "Bujin" monsters with different names from your Deck to your hand. You can only activate 1 "Bujinunity" per turn.
Searches your deck for 3 Beast-Warrior-Type Bujin monsters.
Puts Bujingi monsters into your graveyard.
Returns Bujin monsters from your graveyard to deck.
Discards your entire hand.
Must select Bujin monsters with different names.
Set all your spell/trap cards before activating this card to minimize the cost.
You can activate Bujinunity when you have only 1 hand card to gain a plus 1, or when you have 2 hand cards to not lose card advantage.
Bujin (not Bujingi) monsters have no use in the graveyard, unless you use them as cost to summon Bujin Hirume. So use Bujinunity to return them to the deck and search them out again. If you discarded a Bujin monster with Bujinity, you can banish it to special summon the Bujin Hirume you searched out.
Some Bujingi monsters activate their effects when then are in the graveyard, so the discard cost of Bujununity might not be that big of a minus. The Bujin monsters you searched can then be summoned and are what these Bujingi monsters need to activate their graveyard effects.