You can trigger the effects of these face-down cards by destroying them. Wild Tornado selects 1 face-up monster and destroy it. Dark Coffin makes your opponent choose between discarding a random card from their hand or to destroy 1 monster on their side of the field. And Statue of the Wicked lets you summon a Wicked Token on your field.
You can use Bluff Trap every time your Life Points decreases by 1,200. It lets you have a set Statue of the Wicked on your field which can be targeted by Greenkappa.
Using Shallow Grave allows you to re-use Greenkappa if you only have few copies. Special summoning it from your graveyard to protect you can sometimes force your opponent into attacking it. Useful to bring back if your opponent has multiple set spell/trap cards.
motherfucker is u, because ur mom is being bang in mouth since the night u were born.
in the Italian card, the effect doesn't refer to set s/t cards; it literally says "flip: choose two s/t targets cards, destroy that targets". I read now the English version
Is it optimal to have 2 copies of Kappa in a deck, or one is just fine? Btw, I have 3 Wild Tornadoes already. I don't like the silent magician so I won't reset because I have already 2 kappas (got lucky on guaranteed SR draw)