I think Overlord of Boilerbilges will be a one-of but Overlord of the Hauntwoods will see play as a 4-of
While it doesn't have the threat of being targeted for removal thanks to shroud, it does require 100 mana to be pumped into it in order to actually win with it
After much consideration, here is my list (which, unfortunately, I know I should have included Tainted Pact on, but I did not, sorry)
Blue-Red Big Noncreatures This deck is an interesting take on two things we've seen before: noncreature spells and big spells
Aerith Gainsborough's second ability triggers just once for each life-gaining event, whether it's 1 life from Al Bhed Salvagers or 3 life from Balamb T-Rexaur
Sephiroth fits beautifully there, helping to smooth out the curve in a deck that often lacked a solid three-drop outside of Grist