You may choose the one you put into the graveyard with the first mode, if applicable, or ones that were already there
So, it is a very useful Ability to use to score some strategic points
Getting protection from everything is definitely one of the better things you can do at instant speed, but when you can do it all, Reclamation SageReclamation Sage becomes a two-for-one, Hammer of NazahnHammer of Nazahn is a combat trick that leads to more combat tricks, The Meathook MassacreThe Meathook Massacre is a catered board wipe you can engineer into a combat step, Narset, Parter of VeilsNarset, Parter of Veils is even meaner than usual, and you can cast your Treasure CruiseTreasure Cruise instead of losing it the next time you put a Wheel of FortuneWheel of Fortune on the stack (actually you need to do that in the reverse order)
Its one card among 99
Heard of the term 'recession indicator'
If you exiled a nonland card this way, create a Treasure token. More creatures is good, and Treasure tokens are famously absurd, so this seems like a great card in Lost Caverns of Ixalan