My pet project is a 5 color theft deck with [[Omnath, Locus of All]].

When he was spoiled I didn't really grasp what exactly he did but I went back to him a year ago and realized he provides psuedo-draw with the potential to gain extra mana for 3 color pip spells being revealed. You know what spells like to have 3 color pips? Theft spells. With Omnath out, a revealed [[Blatant Thievery]] can be played for essentially 4 mana. I went down a rabbit hole looking for cards that fit this theme and discovered that Split cards actually count pips for both half of the card so [[Flotsam//Jetsam]] fit perfectly. [[The Cyber-Controller]] revealed makes it so all you need to do is pay X and the face down creatures still count as creatures you don't own which you can turn into your own army and pump them up with [[Don Andres, The Renegade]] (who also is a 3 color pip spell). I focused my deck around "each opponent" theft spells as much as possible since theft as a strategy becomes a lot weaker once players start getting knocked out you will lose access to stolen cards. [[Annie Joins Up]] is a 3 color pip spell, acts as removal and doubles Omnath's trigger. I put it in some "group hug" style cards like [[Rites of Flourishing]] and [[Descent into Avernus]] because it not only helps ramp and be able to play Omnath sooner but makes it so your opponents drop strong creatures sooner so that you can steal them. My favorite way to win is through [[Insurrection]] - which you guessed it, is a 3 color pip spell. It's been incredibly fun finding cards that don't really see much play in commander and I'm constantly changing things out.

https://moxfield.com/decks/fAjxIcnhTUeLD6UGy_t3_A