No minimums
The kicker (not the mechanic) is that if you Saddle Caustic Bronco your opponent is the one who loses the life instead
Whispers in the Well makes a lot more ink color combinations viable, and brings some truly powerful landmark cards to the forefront
All their cards have custom art, making them easily recognizable as proxied cards, but the art is at least visually exciting, and itll match an entire deck
It's generally fairly rare for a spell to mass remove Planeswalkers, so In Garruk's Wake is a powerful spell to slot into your Commander deck
While it's a fine card and scales throughout the game, there are a ton of graveyard-centric / reanimation decks in Commander, and it seems unlikely that Gyrus, Waker of Corpses will beat out most of the pre-existing options outside of something like Jund Hydra tribal (and then, it's not even that good with many Hydras since they are X-creatures, which won't work with the reanimation ability)