Avoid Mind Stealer since he can play with a copy of your own deck (although it's fun to have him cast Contract and then win his anted copy of your own card!) Paladin is also touchy, with Karma and Northern Paladin to work against your black deck even before he starts with his Magical Hack and Sleight shenanigans
While it's not a requirement to play the game casually with your friends, if you have valuable cards, or if you're playing in a tournament, you absolutely need to have them
A bittersweet dirge is sung
It also requires direct contact with other humans, which can be a deal-breaker for people who prefer the comfort of automation instead
And thats just because mutate is such a fun space to play in, with multiple commanders that can take advantage of this spider
Storm comes with the Ceaseless Tempest ability, which causes instant and sorcery spells to gain the Storm keyword whenever Storm deals damage