So Nintendo tiers, yes, but I've been using Delphox battling against players on the cartridge and I feel it has two real viable sets: Specs and support. You can do a lot worse than 75/72/100 defenses but as mentioned its unfortunate typing cannot be overstated when it's weak to some of the most common priority. You will rarely find opportunities to get a CM up, if you are lucky enough to get it on the field in one piece. I would say that it will replace whatever void Charizard left in the lower tiers for strong, fast, special attacking Fire type; in fact, Delphox may be slightly superior due to better SpD & Speed and no 4x weaknesses. Psyshock is arguably a better and stronger source of secondary STAB than Air Slash and it gets some interesting support options.
114 SpA is nice enough to make use of Specs. As mentioned, Psychic STAB is better than what most Fire types in the lower tiers offer and its movepool isn't too shallow. I've been running Flamethrower / Psyshock / Grass Knot / Shadow Ball for decent coverage (I play on the cart so too lazy for HP). I've been lucky that no one has been using Houndoom in lieu of flashier Megas. I guess Scarf could be nice too but it really needs the power for something that just cannot set up.
Wish and WoW are a pretty potent combination, especially since WoW's accuracy was buffed. I actually feel pretty bad that Delphox has supplanted one of the few things Flareon could do. On a support set, Mystical Fire is viable as an attacking move to cripple Pokemon who would otherwise spit on WoW (though admittedly some carry Flash Fire).
Also Magician is a pretty gimmicky ability, if not worthless. You need to be itemless for it to even work, but why lose a potential OHKO that Specs or even LO offer? Why steal an item when you can cripple or kill that Pokemon instead? Even support sets could use Leftovers or a resist berry.