I also want Ancient Curses, which requires a quest, of course.
Doing Slug Menace will provide me access to Proselyte armour, which will help with slayer.
Guess I've got some questing ahead of me... 5 quests.
Doing Blood Runs Deep provides 450k prayer xp, which would help me amazingly, but requires so much I don't have, that it can wait for another day.
Doing Path of Glouphrie would also be a good idea, as it gives 20k slayer xp, and provides access to a new slayer monster, Warped Tortoises.