Zenith: Yeah. Time's up. *punches a hole in Masterman's chest*
Zenith averting Nuclear Armageddon at the end of Book II with the use of his newfound powers and his own cunning.
Red Dragon's face-off against Masterman. At once a CMOA for the former, and then also an extremely large shock.
An anguished Big Ben in Book III reflexively picking up a FREAKIN' AIRLINER and hurling it at the evil superhuman who's just killed his friend. As well as his final confrontation with A-Man. "I did it, didn't I?...NOT a failure!"
Also from Book III: Tiger Tom and Tammy's final moments. "Make a wish and..." "Dirty, dirty little children....oh no." - "Oh, YES." *KA-BOOOOOOOOOM!!!!!!*
Zenith and Peter St. John saving all of existence in Book IV as only two proper prats can.
Zenith seeing through Peter St. John's manipulation of Tony Blair.