In the end, it's a nice ability, which presents an interesting trade-off between flexibility and surprise effect
While trying to think of things that were host or augment-like, I realized we had a brand-new mechanic coming up in Ikoria: Lair of Behemoths that fit the bill, something called mutate
Card Name Mana Cost Type Legendary Creature Human Wizard Rarity Mythic Rare rules Text : Choose a card name that hasn't been chosen from among Disenchant, Braingeyser, Terror, Shivan Dragon, Regrowth, and Black Lotus
You can only partner these commanders together, as the text says PartnerCharacter select
Attacking with a goaded creature doesn't cause it to stop being goaded
Part of what made Commander special was that it was a community-created and managed format