You can also look to leverage spells which implicitly allow cooperation between different players, such as Discerning Financier, the various curse-type auras, voting spells and similar effects like Councils Judgment or Lavabrink Floodgates, and damage redirectors like Stuffy Doll or Brash Taunter
Blightsteel Colossus is one of the scariest creatures around and a popular target for artifact decks to cheat into play
Were going Grixis, were going big and were going hard
As for closing out games, there are a few options
If we had to point to our biggest problem with his design here it would be the fact that he has the top half of a fully grown man and the bottom half of a toddler
You play a turn 1 Amulet of Vigor and then play a green bounce land on turn 2, untap it, float mana, and bounce it to its own ability to use your floating two mana to cast Summer Bloom