Possible cards to put inJace's Phantasm. Will be up to a 5/5 quickly and a cheap dropJace, Memory Adept. because insta kill with a guildmage if it drops. although i feel it might be a bit of a target and its expensive both $ and manaDeath's Approach. gets rid of annoying cards. maybe sideboard inNegate . cheap counterspell simply but depends what deck im playing againstMind Sculpt. mills and pumps the aberrations quite hardWhat i could removeDying Wish i like it, if a sac a pumped aberration with consume flesh i get massive lifegain and maybe kill them in 1. also makes a decent deterrent for them to kill stuff. but vulnerable to bounceNephalia Drownyard . yes i understand its good in a mill deck but for the cost i can make much more happen. Maybe a Rogues' Passage making an unblockable abberation and activating the guildmages
card:Sage's Row Denizen might be up your alley for this.
card:Rogue's Passage is thrifty, but expensive, especially to be used every turn. Plus, for the number of dual lands you're running (4 of both shock/tap, and 2 guildgates) having more colorless symbols might not be the best choice. I would suggest Artful Dodge to have an instant access to unblockable.
Speaking of Consuming Aberration , you should try running four.
All in all, I really dig this. Dimir is stupid powerful right now and nobody is really checking it because they're obsessed with Red and Esper. Be cautious that you won't get outsped by Red, though.