You are thinking defensively. Make a thief who can cast Heat Metal, which requires a bonus action to trigger. They can then hit it twice in a round AND there's the Pyroquickness Hat which gives you a bonus action if you do fire damage (it burns you too, get something for fire resistance). Alternatively, if you also have the Helmet of Grit and go under 50% HP, you get another bonus action.
Ninth level Druid (for level 5 spells) + third level Rogue (Thief) for Fast Hands. Upcast Heat Metal to 5th level for 5d6 damage. Get the hat. Do 15d6 to a target each turn...
