The first set of kanji appear to be a term pronounced either tenjin, amatsukami, or tenshin. Looks like it can refer to a specific god "Tenjin", or a term for "heavenly gods" in general. I'd focus on this as one part, and the other two kanji as another part.
Options here would be things like "Celestial Deities" or "Divine Lords". Basically any suitable synonyms.
Next part, 怪戦 is from a cursory search, used primarily in this game. Basically it's a bit of wordplay on "Kaisen" which has three spellings, 会戦, 回戦, 開戦. These mean stuff like "battle", "match" and "start of a war".
So take those known words and definitions, but swap out the first kanji with "aya/kai" from "ayashii" (suspicious) and "kaiki" (bizarre) and you have the "Kaisen" that appears in this game.
Judging by the title screen and enemies, I'd say this give it a supernatural twist. The "kai" used here is also used in "kaijuu" (monsters) and "kaidan" (ghost stories).
so "Phantom War"?
Take your pick of that kind of stuff.
You're going to end up with something like, Divine Lords Monster Battle, or Celestial Deities Spirit War. Alternately you could keep Tenjin, and do Tenjin Phantom War or some such. If you can find some word soup that sounds good, I'd say go for it.