his weakness is water and fire?
those 2 elements are opposites from each other and your rhg is weak towards both....
It makes other RHGs wanna fight you.You can't just ignore your weakness,making it easy for people to beat you because alot of people have elemental based RHGs.
And the darkness part doesn't make since either unless you were like a paladin or something,but your not,sooo....
You should atleast explain in your story.
The weaknesses can contrast to each other you know, he can make his RHG weak to what he wants, not what you think is right, and making other RHG's want to fight him is a good thing, by having a simple method of losing, that means this RHG is not over-powered, which is also a good thing.
You can't just come here and tell him what not to do when he's done nothing wrong, it makes you look like more of the cocky arse-hole than you already are.
Nice RHG. Good luck.