Valkyrie Harbinger + Righteous Valkyrie generating bonus angel tokens.
Playing against an opponent w/ Harbinger & 2x Righteous Valks in play. He keeps attacking w/ the angel tokens & I kill them, then he generates more w/o any lifelink or other way of gaining the 4+ life in that turn! IE: he gets the 2 tokens and gets the boost in life for when they enter the field, which is why he would get the tokens in the first place! It's "FREE BONUSES FOR ME!" day at the Arena! Naturally, I lost since there was no way to overcome his infinite creature advantage. Oh yeah, and let's not forget #FIXtheG!D!SHUFFLER so I can draw something other than land once I finally overcome the initial "Nope, no land for you while we give your opponent a perfect draw..." so it changes to "ONLY LAND FOR YOU NOW THAT YOU NEED ANYTHING ELSE!"