Rex was tired.
He was just coming out from back-to-back wars without sleep. After taking in the whole Blood Spartan Tribe in a single day, he celebrated throughout the night and without rest, he had to organize a defensive perimeter around his territory.
After establishing the defensive perimeter, the Exquisite Gang attacked and still without rest, he was dragged into another war.
After fighting for a long time, killing over a thousand mystic warriors in the process, his fellow leaders finally suggested the assassination plan.
Once again, without rest, he forced himself to go on the assassination. Unlike a war, an assassination was even more draining mentally since he had to be alert 100% all of the time to avoid falling into a harrowing situation or worse a trap.
From an assassination, he messed up and it became another full-blown war until he finally killed Dave and 2 more Advanced mystic warriors.
