Hmm, I'm not particularly knowledgeable about set-ups I haven't seen, but it sounds like a legitimate set-up. I asked around and was told that at some point the mixed shadow set-up would be better because the stats it gives will be more valuable as well as being more useful in a standard magic party (shadow res down). However, it sounds like you need to do some big legendary purchases, so it's up to you whether you'd prefer the slow and cheap grind for Gracia or just outright buying legendaries to make shadow setting (more?) feasible. Mainly you'd prefer to replace Dark Gothic Shoulders with Dead Captain's Bone Breastplate because it would give more shadow damage and useful stats compared to Dark Gothic Shoulders. Blooming Black Smoke Energy for sub-equipment for far more independent attack and extra shadow damage. And Ominous Giant Bat Pants for more shadow damage and shadow res down. With Gigantic Presence set and Code 608, this seems like a feasible set-up to me, but I've never used Gracia on any character so I don't know how strong it might be. On the other hand, what other epics do you have that might supplement Gracia set-up? That might end up tipping the odds.