Spirited Companion -> Ainok Bond-Kin
Cutting Spirited Companion because I'm adding another ETB draw a card creature in this update and I don't think white needs more of this effect. Spirited companion was good in aristocrats and blink however the more expensive variants were better overall. I've been wanting to add Ainok Bond-Kin for a while. If you outlast it once, a 3/2 first strike is a pretty good creature. It makes any other +1/+1 counter card better. I'm not fully adding support for a counters deck at this time, however Ainok Bond-Kin would help if I do.

Cloudshift -> Pegasus Guardian
Unless you have one of the more impactful blink targets like Maul Splicer or Mulldrifter, Cloudshift has underpreformed. Rescue the Foal costs an extra mana over Cloudshift, but adventure gives it some good upside. It essentially draws you a creature you can play later.

Argivian Phalanx -> Salt Road Packbeast
Loses vigilance and a point of toughness, but drawing a card on ETB makes it way better most of the time.

Cyclops Electromancer -> Molten Monstrosity
Cyclops Electromancer has been decent, I just want to try out Molten Monstrosity. If you have anything bigger than 3 power it's a great rate. Big tramplers are generally good in this cube.

Voracious Varmint -> Undergrowth Leopard
Functionally identical. I just like the cat more.