Shifting Ceratops Shifting Ceratops has high power and toughness for a 4-mana creature, with a lot of other built-in advantages
Flash it in on an opponents upkeep, champion a Bitterblossom token, and tap their lands they effectively skip a turn
Green There are two legendary Oozes in green: Slurrk, All-Ingesting, and Aeve, Progenitor Ooze
Glacial Chasm Glacial Chasm exists in a similar space to Solitary Confinement as you need to circumvent the downside, but the cumulative upkeep costs a much smaller price to pay, especially considering all the ways you can play lands from your graveyard
Your opponent adds damage counters to their card accordingly
The one thing that Hedron Archive has going for it that I like is that you can also cast a Hangarback Walker the turn you cast it