The three 7-mana creatures were pretty underwhelming, and Mirroshell Crab was the only one seeing real play, so they were all replaced with cheaper creatures. At the same time, I decided to add a reconfigure creature to each color.

Mirrorshell Crab -> Hypnotic Sprite
Archfiend of Sorrows -> Leech Gauntlet
Chancellor of the Forge -> Lizard Blades

I felt that only red should be able to consistantly create token, so I replaced the blue and black token generators. Moreover, Sedgemoor Witch was way too powerful.

Nadir Kraken -> Acquisition Octopus
Sedgemoor Witch -> Callous Bloodmage

Other changes :

Knight of the Ebon Legion -> Foulmire Knight because it was too powerful compared to the other one-drops

Vampire Nighthawk -> Fell Stinger because the card wasn't really fun to play or versatile

Nekrataal -> Corpse Augur because black already had too much removal and Nekrataal was the least interesting

Filth -> Graveborn Muse because Filth is the worst of all incarnations

Disfigure -> Lash of Malice because the card is more versatile

Flame Javelin -> Electric Revelation because each other color now has at least one draw engine, and Flame Javelin wasn't good enough.