This differs from cards like Karn, the Great Creator, which exiles with a counter and looks for these cards with those counters
First up, a card that triggers the Commander, but can also redirect some damage away from you which will hopefully trigger the other part of YShtola, too
I love that this is an attack trigger and not an on-damage trigger, because it turns your forces into serious beaters every time you swing
The decklists are well known and have a bit of a department store markup only to discount you a bunch if you already have the cards in your collection
Along with giving us something to do on turn one, it loots to fill our graveyard with lessons and eventually makes our non-creature spells cost one less, which hilariously turns Accumulate Wisdom into a literal Ancestral Recall that's legal in Standard, which is super strong