A couple years ago, we started to look into this, and some of that thinking resulted in a few new types of booster experiences
When you cast him, you Amass Orcs 5, mill five cards, and then bring a creature from your grave to the battlefield
Rites of Initiation can also be particularly scary in a Squirrel deck
Corpse Knight Corpse Knight can be a good win condition if you have any sort of repeatable token-creating, blink, or recursion engine
The aforementioned Luminarch Primordial and Meteor Golem come to mind, because with them we can simply wipe out the rest of the board
However, decks such as Turboland, Psychatog, and Rising Waters have found ways to turn the returning two lands disadvantage into a pure advantage, making Gush a card which often gives you four-for-one instead of two-for-one