yugioh phantom knight deck - Knights Core CORI - Chaos Origins Phantom Knights Deck | eBay

While "EvilTwin's Trouble Sunny" provides good interruption during the opponent's turn, mass removal cards such as "Raigeki" or "Lightning Storm" can prove troublesome for the deck, as even if player tributed "Sunny" in response to the activation, the effects of "Ki-sikil" and "Lil-la" summoned by "Sunny's" effect will not activate upon chain resolution before both were destroyed, leaving the player vulnerable to opponent's counterplay

Rampant lifegain is somewhat mitigated by the presence of commander damage, but there are some commanders who arent likely to deal 21 over the course of the game (like Adun Oakenshield or even Karador, Ghost Chieftain)

In Commander, especially, this is often harder than it sounds

Its Explosive Vegetation with Will of the Planeswalkers stapled on