My old DM was a bastard that tried to punish me by limiting my choice to a Halfling Bard, thinking it was a shit character and would die fast. I had some contacts and used them to craft the most kick-arse min-maxed PC one could conceive of, with a rank here, a rank there, all designed to maximise power.

The DM had me split from the party and confronted by the Big Bad. I was more or less done with his bullshit, so decided to kamikaze the bastard.

My said my PC would run up some logs in a logging camp, cast True Strike, cast some spell that increases damage output, leap off of the pile with dual swords drawn, and stab the BBEG.

DM said I could, if I rolled to Cast, Climb, Leap, Attack, and won Initiative - all with disadvantage. I rolled 3 natural 20s and 2 rolls at 18 or 19, and managed to do such damage that I killed the BBEG in one hit.

DM said he teleported away before he died and kicked me out of the group shortly after.