Im thinking commanders like Svella, Ice Shaper, Zacama, Primal Calamity, or Shattergang Brothers
P/T Number 1 Language English Legal Formats Alchemy, Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pauper, Pioneer, Standard, Timeless, Vintage Rulings (11/17/2025) Changeling is a characteristic-defining ability
Head of the Class would fit best in an Orzhov (whiteblack) spellsmatter or heroicstyle deck that plays a high density of cheap instants and sorceries that target creaturessuch as protection spells, pump spells, or removal that can target your own creatureso you consistently trigger Repartee while also discounting a key spell each turn
One way to start the process is to employ the elephant method
For example, if a 5/5 creature that's also a planeswalker with three loyalty counters on it is dealt 4 damage, it's been dealt 1 excess damage and Aegar's ability may trigger
The result is that you get to make an arbitrarily large army of Squirrels