Master of the Feast , Dictate of Kruphix , Mikokoro, Center of the Sea are all solid cards in this deck.

No Phyresis / Grafted Exoskeleton? Also, Cyclonic Rift is hilarious when making people discard / shuffle their hands. Runeflare Trap is also really good.

Forced Fruition seems fun here.

Curiosity is pretty good.

Dragon Mage, Winds of Change, and Time Spiral are more good wheels.

Timetwister is sweet, too, but it unfortunately costs around $1,300.

Next, try out some other good cards:

Notion Thief helps you draw another wheel

Dream Halls lets you play your stuff for free

I see you already run Mind Over Matter + Temple Bell to make everyone draw their decks. It's a good combo, but I'd also run an eldrazi lord to discard and put everything back into your library in case your commander isn't in play at the moment. Ulamog, the Infinite Gyre is the cheapest, so I'd suggest him.

Otherworld Atlas can get pretty insane once it gets over 3 or 4 counters. It helps you pick up wheels and kill the opponents simultaneously.

Next comes more tutors/sifters:

Impulse, Imperial Seal, Vampiric Tutor, Mystical Tutor, Lim-Dul's Vault, Grim Tutor, etc...

Bloodchief Ascension and Kederekt Parasite are more "chaos-wheel" enablers.

Hope this helps you out.

Hey. Day's Undoing DOES WORK, and is one of my favorite wheels in my Nekusar deck. The only drawback it actually has is you can't fork it. The Gatherer says:

"If any triggered abilities do trigger during this process, theyre put onto the stack during the cleanup step. If this happens, players will have a chance to cast spells and activate abilities, then there will be another cleanup step before the turn ends."

So you cast it. Everyone wheels. Before anything else on the stack, move directly to your Cleanup Step (skipping your end step). THEN the pain/damage triggers go on the stack, priority passes, and you end your turn.

Also. I'd love to hear what you think of my build!

Always a fan of Grixis and wheels! +1 from me. Have you ever thought of using Personal Tutor to obviously tutor more but also set up an easy miracle cast Reforge the Soul? It works out for me here Nicol Bolas' Machinations.

Any consideration to Magus of the Wheel for another, well, wheel effect?

Whaaaaaaaat? I love it. Didn't know it existed.

It just came out in this past year's Commander supplemental product. It was in the R/W deck, I believe, which not many people paid attention to aside from Blade of Selves. Which by the way is funny with Psychosis Crawler. Swing with the Crawler, get a ton of tokens, then with the delayed exile trigger on the stack, Blue Sun's Zenith yourself and drain everyone at the board for a super amount of life.