Emrakul, the Aeons Torn 15 Toughness Emrakul, the Aeons Torn is not our #1 highest-toughness creature, but its probably the #1 creature in MTG to cheat into play
Liliana's Triumph 5/10 Not much better than Diabolic but certainly in no ways worse and so will just always get prize of position over Diabolic when the situation arises
On arrival to the battlefield, it will counter any instant, sorcery or ability
Other colors generally put restrictions on the specific card type you can tutor for, such as blue tutors looking for instants and artifacts, and white looking for artifacts and enchantments, but not black
Elemental Bond is probably the one Id get first, because it can trigger off of tokens, has no restrictions to how often it can trigger, and gates the trigger at three rather than four
What the Corrupted card does is varied