-When the villain divulges his entire master plan at the singular moment before it is fully executed, allowing a tiny opportunity for the heroes to think of "something" (some bullshit) and thwart them just in time.
-Also, when the villain becomes absurdly stupid and gets defeated after looking invincible and in control the entire time before.
-A character that never loses a fight. (I'm looking at you Erza from fairy tail)
-The power of friendship
-The absence of fatigue or repercussion from injury