Looking to the new Assassin Creed cards we can add Basim Ibn Ishaq to that list, as well as Ratonhnhakton, and Eivor, Wolf-Kissed
Once the lock is setup we have plenty of time to win the game
Feathers ability is also useful if youre casting an instant or sorcery that has a different replacement effect that kicks in when it would normally try to go to the graveyard, such as being exiled by Dreadhorde Arcanist or Past in Flames
It also plays better with Yorion, having an ETB that reliably sticks on the board and gains you life to help stabilize
The most confusing part though is that narrative
If it's a permanent spell, the copy gains haste and "At the beginning of the end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.) Creature - Beast Demon Copy (CTRL to add secondary) Draw Artist's Talent (Gain the next level as a sorcery to add its ability.) Whenever you cast a noncreature spell, you may discard a card