The card is a fantastic reanimation target for Yuna, Hope of Spira when Omniscience isnt lying around, and can double as a win condition if you do manage to resolve the infamous blue enchantment
Descend X or fathomless descent, on the other hand, are ability words these are a way for devs to let us know that cards with those ability words have a thematic connection, but each card handles things on a case-by-case basis
You really need to be playing all or basically all islands for this to be viable in cube and that does for it in terms of playability
When you open the MTG Arena app and go to the Store tab, you will receive your redeemed items
I like the last ability, but if you slap this in the command zone, its for the mana
(Remind me when Worldwake is public and I'll tell you about it.) One of things that is very subtle about planeswalkers is how we try to craft their abilities to match the kind of wizard each of them is