Misery loves company
I could not win this fight, despite my efforts. Mons used were level 30 (I haven't taken anyone over that). Just hoping the reason I lost is because of the strength of the opponent and not my own lack of skill.
She had dazzling gleam with (I believe) pound. I didn't really pay attention to the quick move cause I just had to deal damage.

Answers
Like I said, don't really remember the quick move. Used some gyrados, Rhydon with RS, Gengar (hex/shadowball), Vaporeon, Alakazam (but PC got nerfed...). Tried having a one bar charge move ready before I faced her.
I'm only level 32, so 33.5 is the most I can reach. Will there be a noticeable performance increase from 30 to this?
Powering from 30 to 33.5 is like 1.75 normal rate powerup, it maybe changes the outcome if you losed by timeout for 5-7s (just estimate). I am big dust spender though normally sit on <10k dust just pwup iv90+ attacker or defender I want to max at that time.
One more question did u dodge? only charge ? or all quick and charge?
One of my local enemy gyms has a 25xx Blissey followed by a 28xx Blissey, with a 28xx Gyarados on top. I can just barely beat the little Blissey with my old best attackers (that aren't in gyms): level 30 Alakazam (PC/P which got nerfed), and high level flareons and arkanines.
I just hatched a 96% Gastly, evolved it into a Hex/Sludge Gengar, and powered it up to level 29 so far. It definitely does better than my legacy attackers since the little one is Pound/Dazzle and Gengar resists both. Blissey resists Hex, but it's the best quick move for Gengar vs. Blissey because it charges up Sludge super fast. I need some more potions and another stronger attacker before I try making a dent in that 28xx monster though.