Wind and Thunder both are difficult to play, while water provides balanced SSRs and strong SRs.
It depends on your luck, what you get in the future. You really need 1 or 2 good SSRs more for Wind or Thunder to be competitive.
Gaia is strong after awakening. Atm Gaia is pretty crap (The reason why she gets awakening so early)
Raiko also needs some others SSR like Hua lin to shine.