Bill Cipher

Weirdmagedon 1:At the beginning of opponents turn, their cards gain a touch of madness and deal negative damage
Weirdmagedon 2:When this card comes into play all creatures join forces and combine all stats and abilities for 1 turn, sacrifice them to the graveyard
Weirdmagedon 3: All your cards have the first 5 effects you can think of and +5+5