Once you've chosen both modes for the spell, it doesn't matter whether you continue to control a commander
So it provides defense and card advantage
When you boot the game up for the first time, you have the option of migrating your account from Online
While Survival was always an extremely over the top way to search for creatures, the interaction with Vengevine actually turned it into an incredible mana engine to boot (letting you play as many Vengevines as you want for just one mana each)
A pretty perfect card, if Im honest
(I always imagine it like being what youd get if chess had certain edge cases where rooks could fly, bishops could teleport, or for a second, pawns were driving tanks.) Since the game is built around several thousand collectible cards, and almost every card has some additional unique ability to it one way or the other, it creates an endlessly manipulable, constantly surprising experience