While he can be your commander, he usually sees play as a creature under commanders like Adriana, Captain of the Guard and Wulfgar of Icewind Dale where his attack trigger can be taken full advantage of
Emrakuls Messenger Rating: 4/10 You dont need to do much to sell me on a 2/1 faerie flier for 2 mana like Emrakul's Messenger
You can also try to create synergies within your own deck, whether it be with Deaths Shadow as mentioned above, or my personal favourite in Legacy of casting it at your opponents end step and then cast an Uro, Titan of Natures Wrath a three-mana 6/6 creature
Kozilek's Unsealing Two generic, one blue Enchantment Devoid (This card has no color.) Whenever you cast a creature spell with mana value 4, 5, or 6, create two 0/1 colorless Eldrazi Spawn creature tokens with Sacrifice this creature: Add one colorless mana. Whenever you cast a creature spell with mana value 7 or greater, draw three cards
If these two lands two could swap reprint frequency, that'd be great