Its an incredibly elegant and carefully designed solution to the onboarding problem that a lot of TCGs have, and I wouldnt be surprised if other card games look to this for their own equivalent in future
The creature side of things is Questing Druid, a two-mana green 1/1 that reads: Whenever you cast a spell that's white, blue, black, or red, put a +1/+1 counter on Questing Druid. In the right deck, this card isnt just card draw but a terrifying threat, as it could grow absolutely massive fairly quickly
How Do Battles Work in Commander
When Nine Lives leaves the battlefield, you lose the game
You must follow the normal timing permissions and restrictions for each exiled card
If a defending player blocks the creatures in a log attacking in their direction, other defending players aren't obligated to do the same