Since I have been taking a more focused approach on the thematic compatibility side of things, I got to thinking and I decided that I could lean a little bit more into the mechanics that comprised Theros. That's why several of the new replacements have Scry as an ability and are directly from the involved sets as opposed to straight up ambiguous replacements. Elo and interaction did have a hand in the choices.

Changes of note:

Master of the Feast is awful in 4 player commander when everyone has 40 life, card advantage is too valuable to just give other players for free. By the time you get to attack with it even once, three additional cards have been drawn off of it. I wanted to bring back Tymaret, Chosen from Death as he allows for graveyard hate, which could be pretty useful in this cube.

Primeval Titan This could be either a really good or really bad addition. I wanted to add another Titan to the cube since I can't really do much with the multicolored Titans that are actually from Theros. At least with Primetime, whomever plays it will become public enemy #1 and hopefully will be late enough in the game other players will be able to respond. Additionally, there really isn't any bomb lands to be grabbed, leaving him mostly relegated to ramp and attacking which can still be a huge issue on its own. I think it will balance itself out, but that's yet to be determined.

Kydele, Chosen of Kruphix lost a lot of her support with the reduction blue card draw, so Thrasios, Triton Hero is the replacement and I think a pretty good fit overall.