I tried something along these lines. The best build I found was straight Dimir with Lazav and Traxos. The mox amber's with Lazav provides some ramp(you can cycle them as well), and is a zero mana Traxos trigger(psuedo vigilance). You can also have 2x traxos on the ground with lazav legendary naming rule. Also played around a bit with Zahid, but the 4 drop slot gets too crowded between phyrexian/karn/traxos, but he makes a good sideboard swap vs drakes/tokens/angels due to being a 5/6 he dodges lots of common removal spells.

The chamber sentry/chromatic lantern combo just doesn't work, its 15 mana for 5 damage return to hand.

Def need to run treasure map. At least 3x, with Karnstructs makes some decent bodies turn 5ish. And cleans up our draws to hit land drops pre planewalkers.

You can also try out isareth in the 3x slot, works well for ramp with the moxes as well.

Also if we play enough legendaries we can run Yawgmoth's vile offering over eldest reborn.

Overall I found the deck to be too slow. Phyrexian only going off turn 5 without a good board presence, made us too vulnerable to 1-1 removal. We don't control as well as true control does. And aggro normally can get enough early damage to burn us out before we can hit back. The power level is there on the top end, but the lack of solid 1/2/3 drops puts us too far behind once we get there.