The most fireballs you can cast in 1 turn currently is 4 if you expend almost all of your resources, and if you could generate just one more level 1 spell slot to gain 1 more sorcery point you could start a fight with a fireball, then proceed to cast 4 fireballs on your first turn.
To do this you need Circlet of Fire for an extra bonus action for non cantrip fire spells, which fireball obviously is. Generate 2 extra level 3 spell slots by turning level 1 and 2 spell slots into sorcery points then into 3rd level slots. Drink a haste potion before the fight. Now you have 2 actions and 2 bonus actions and if you turned enough level 1 and 2 spell slots into sorcery points you should be able to quicken 2 fireballs.
You start with 5 sorcery points and need 2x5 for level 3 spell slots and 2x3 for quickened spell. You can generate 4 + 6 with low level spell slots and an extra 2 with your Ilithid power and 3 more with Spellthief converting the gained spell slots into sorcery points. This means you can expend all your resources for 4 fireballs in a single turn and have 4 sorcery points remaining, just one short of an extra level 3 spell slot which would allow you to start the fight with an extra fireball making it a total of 5.
No fight in the game really lives past 2 or 3 except ones that have fire resistence or immunity.
This breaks 2 5e rules, the multiple leveld spells one that was mentioned and also the action granted by haste should be restricted to: That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.
I know this is a game and all that, but setting your sword on fire with a candle seems a bit silly. Not to mention that a sword being on fire would only harm the wielder but that's beside the point.
Last edited by EldritchBlastEnj; 08/01/23 09:06 AM.