Finally I would cut some of the redundant slivers for flexible tutors: you don't need Galerider Sliver and Firewake Sliver when you can just run Cloudshredder Sliver and a bunch of ways to tutor it up
ANCIENT ADAMANTOISE Hard to remove, protects you and your board from damage, and drops treasures when it dies
If Archfiend's Vessel leaves the battlefield while its triggered ability is on the stack, you can't exile it from the zone it's put into, so you won't create a Demon
Of course, theres the fact that they can be used as theyre intended as a game
To get the tasty details on how things came to pass, go farther back than Phyrexia: All Will Be One story if you can, and check out the flavor in the lore and story summaries
It's not a bad retirement plan, to be honest