While it is important to consider strategies and card types, it's also important to make a deck that feels unique to your play style
In terms of common removal, both Caustic Exhale and Dragons Prey are solid options
Elesh Norn isn't often a commander, though it's more popular in the deck of 99, and it's also a popular reanimation target in other formats such as Modern and, in years past, Standard as well
Pramikon, Sky Rampart | Illustration by Richard Wright Put simply, defender is a static keyword ability that says that the creature with defender cant attack
(Or it might be the worst
If you get hit with the Embalmed Angel Zombie and cant remove it, you are down a permanent and a removal spell and they still have the Angel attacking you