I see rainbow as Time-Centered.
In the first god batch, there was a god for each element.
Gemini
Fire Queen
Incarnate
Morte
Seism
Chaos Lord
Hermes
Graviton
Ferox (bugged)
Miracle
Rainbow
Scorpio
I can see your point of view, but this is currently what I 'perceive' to be the FG 'elemental' alignments including all of the recent ones:
= Gemini + Paradox
= Fire Queen + Octane
= Incarnate + Decay
=
Morte = Seism + Obliterator
= Chaos Lord + Dream Catcher
= Hermes + Eternal Phoenix
= Graviton + Dark Matter
= Ferox + Elidinis
= Miracle + Divine Glory
= Destiny + Osiris
= Scorpio + Neptune
/ 'Other' - Rainbow
This listing shows two major things: most of the
FGs uses mostly towers exclusive to that element (Paradox may have a
Mark, but he
uses Towers in his deck, same thing like Gemini (who uses a few
towers as well)). Rainbow only has Quantum Towers by this definition, so it's not counted as a Time FG (compared to Destiny and Osiris, who use more Time towers than him). Morte is the only one who uses
Towers by this current match-up, which leads me to the conclusion that he's the only 'Death' God around, even if Scorpio uses more poisonous tactics to bring his/her foes down.
The other thing is that each of the FG's also use creatures that benefit greatly from that synergy in question: Paradox and Gemini use Twin Universe to copy heavy-hitters to ruin the opponent's flow and put them on the defensive for example. Seism and Obliterator have specialized permanent control (Quicksand and Pulverizer respectively), alongside tough protected defenses (Diamond Shield + Protect Artifact = ugh). Destiny and Osiris utilize Eternity for anti-deckout and generic CC against players, etc.
...anyway, that's just how I see it. ^^; Wouldn't it be awesome if we could just have more FGs implemented in the future though? XD