Valor

Two sources, both random, both tied to the dungeon. Opening gold chests once Skeletron is down is the direct route, and the golden lock boxes that come out of dungeon crates roll from the same table, so if the chests are not cooperating you can fish for it instead. No enemy drops it, so there is nothing to farm on a timer.

Hold the button and it stays out, which turns the class into a positioning game rather than a clicking one. Park the yoyo inside something and walk backwards while it grinds. String and a counterweight change how it feels more than a small damage step does, and the yoyo bag rolls both into one slot, so that upgrade is worth chasing before the next yoyo is.

The name and the small symbol at the end of the tooltip come from a real yoyo manufacturer. Several other yoyos in the game are named after that company's products.