Dimaria is basically a war goddess. I don't think she's ever been defeated in battle before now. She's the vessel of a God, which in itself makes her very unique. She's definitely in the top 5 Spriggans. What's seen as "generic" is merely confidence in her own skill, she's not one for false modesty which I like quite a lot. She's done a complete 180 now after being defeated and is much more serious. Sure she's tied to Brandish, but Brandish is only relevant because she's tied to Lucy. Both are powerful mages but if you're not Fairy Tail or tied in some way to a Fairy Tail mage then you're bound to fade into the background eventually.
As for not "having anything" you need to consider who she's been up against. In all her "partial fights" such as when she faced Kagura, she clearly had the upper hand before they retreated. She met her perfect counter in the Wendy/Sherria/Ultear fight, then was unfortunate to capture Natsu and Lucy, only to come up against partial END. Only the to 3 Spriggan will really have an overall effect I think. And one has already fallen. So holding this against Dimaria is a bit harsh.
Nothing that puts you as a good character in technical terms. Everything she currently has, places her with a middle character (and I'm leveling for fairy tail, even the principals have poor development)
She is god of war, cool. And so? All you can do is assume that it will be crafted because it is a shell of a god, just like I said, that it could be development with flashbacks of brandish / would-be friendliness explaining why such an obsession.
Are things that improve the character, BUT NOT HAPPENED. It's just guess.
I am analyzing the character in its pure essence. Not based on what she could be the author to work on.
And she is a villain with a villainous villainous personality, with beauty (which is not merit, since all are beautiful) and a good magic (ours is strong, cool)
Taxing a character who only has this as a good character, is a lack of daily Reading.
I'll start using your argument.
Our, bradman is a great character ... he has a cool personality and does not measure efforts to annihilate with the enemy ... besides having a badass appearance and his ops spells.
He is a demon that uses all the curses ... Zeref created it? Or did a human absorb the curses and become that creature? (Saw, I'm picking up a trait of the character and guessing how the author could work it.