In Partner decks, this usually means duplicating a commander that already provides value , which is why Sakashima is often mentioned among the top blue cards in MTG for synergy-driven Commander builds
Toxic also has a design history in wither from 2008's Shadowmoor , an ability converted damage into -1/-1 counters to creatures and regular damage to opponents
Take a look at three alters done on Karador, Ghost Chieftain by Luke Emmerton of Luey Dragons MTG Alters, Cromat by Sally Stokes of S2 Alters, and Breya, Etherium Shaper by Brandon Brown of Modfly Alters
Grizzly Bears will act as my baseline for this list
Korvold is a great choice for anyone that wants to sacrifice their own stuff, and for me, is one of the best commander cards mtg has to offer for aristocrats lovers
Bloodlust Inciter: I really like this card