I probably wouldn't use this, but it's too awesome of a thing to not have in the game. If they're going to do this for Sepiks prime, I'd like to see it happen for other bosses too. Maybe an Atheon themed one that could drop from Vault of Glass (when they bring out a max level variant of it), or maybe a hive themed one from Crota's end? More boss-inspired stuff in general would be cool. Part of the reason I loved Festival of the Lost so much.