You're a sorcerer. You are 6th level and thus have three 3rd level spell slots, and you know Fireball.
You took a potion of speed last turn, and you are wearing the Circlet of Fire.
You:
1.) Quicken Fireball as a bonus action. It deals 8d6 damage to enemies within a 20-ft radius, Dex ST for half damage.
2.) Cast Fireball as an action.
3.) Cast Fireball as your second action.
4.) You have a bonus action because of the fire spell. Idk if BG3 lets you cast a 2nd Quickened Spell; we'll be pessimistic and say "no" and so you "cast" Shove or Hide.
In total you have cast three Fireball spells in one turn. It's unlikely that all the enemies failed their saving throws, but assuming they did and you (pessimistically) hit 4 enemies with each fireball, you would have done 96d6 points worth of damage. 24d6 to each enemy if you hit the same enemies each time.
More realistically, we'll assume that enemies save 50% of the time (so 72d6 total damage). Each enemy, assuming you hit them with each fireball, will on average take 18d6 points worth of damage (Scorching Ray, at a 70% hit chance, on average deals 19d6 damage).
Add in the Gloves of Flint and Steel. Idk if lightning charges affect ST spells, but add them too. Also you have Red Draconic Ancestry; so "at 6th level, spells that deal Fire damage are more powerful." And after the fight, you long rest to restore all your spell slots and sorcery points.
I don't think there will be many encounters in the game that can withstand that.
