Thank you so much for your time and ideas! Here are some of my thoughts:
It sounds like you might be a blue fan....so I'm sorry. I'm hesitant to splash it in, as there aren't very many low-cost artifacts to make affinity work in the deck, and the creatures die to
Worldslayer. It's also partly personal preference, since I have more experience with faster, creature based decks, though I think you're totally right that adding control and taking time to set up the combo would work equally well in the long run.
Enchantments like
Indestructibility and
Gift of Immortality also die to
Worldslayer, though maybe
Rancor would work to get trample damage in? Not sure...
However, I think splashing black for discard and removal is a brilliant idea, to take care of any remaining threats in the hand (or field). The first things that came to mind were
Dismember and
Inquisition of Kozilek, though there are probably better options.
Because lands get destroyed with
Worldslayer I think I should replace
Rampant Growth with
Darksteel ingot, and 4 Forests with
Darksteel Citadel, so that I can play
Inquisition of Kozilek (get rid of cheap spells) or
Dismember (maybe on an indestructable creature?) even after wiping the board.
Probably not exactly what you had in mind, my apologies, but thank you again for the great suggestions. Cheers, and godspeed