yugioh herald deck of Pure Light - Yu-Gi-Oh! Card Database When your opponent activates a Spell Card What even is this thing

You can also choose to transform Etali, Primal Conqueror with nine generic mana and one green Phyrexian mana (pay two life or one green mana) into Etali, Primal Sickness , an 11/11 Phyrexian Elder Dinosaur with Trample and Indestructible

Still, thats extremely narrow and would more than likely be better off dedicating the slot to another removal spell, even if its a burn-centric one like Pharikas Cure

And I mean I cant disagree

You can only use each effect of "Fiendsmith's Desirae" once per turn

It lets you keep a creature of your choice, and it also exiles graveyards on the way out

This TCG has a reputation for being pretty convoluted, thanks to its massive library, deep mechanics, huge amount of strategy, and sometimes unintuitive rulings