Bubel

Soul's fire is fling for 1 extra mana that doesn't kill the creature. Add some as a contingency.

Why did you choose the worse Bolas? God-pharaoh is better in brawl...

At first, I didn't get it, but now I like the idea of cheap changelings filling in a variety of tribal cards.

I like Rakdos, but the black here seems so minimal as to be pointless.

MAXIMUM INDEPENDENCE

Fun deck idea, though. In 1v1, this would be devastating.

The name alone warrants a like.

Is this supposed to be a commander deck? If so, you're kinda missing the idea. You can only have one of each card (besides basic lands), and you need exactly 99 cards, plus your commander. And, honestly, though I love Yargle, You have a way better commander in Gisa, who can turn Yargle into 9 2/2 zombies. The idea's nice, but it's not a commander deck.
Also, you need sol ring in any commander deck.

NVM, just cut soul summons. it wasn't doing much, and hushwing gryff is dearly needed.

Turns out that dark ritual isn't legal in modern, it's too old.
I saw the idea for soul summons and dreadnought online, so I can't really take credit, but I decided to include it anyway.

I took it out and added in some more low-cost infect creatures, along with some mutagenic growth.

EDIT: I added it in and cut a bit of removal/pump.

I didn't know it existed. What would you recommend cutting to put it in?