Stole his powers to use illegally against the order of his superiors
Gained and used his powers as part of the KO-35 resistance
Once disguised as Santa Claus to help draw the Neziranger's attention away from Miku.
Once disguised as a clown to help draw the Psycho Ranger's attention away from Cassie.
Told the others about his transformation weakness. Later as he was working to get the time limit fixed, Miku and Kenta thought Yuusaku was dying until he later set them straight after the battle, confirming to them that he has a clean bill of health to which the others scold them for their misunderstanding.
Did not tell the others about his transformation weakness and when Alpha 6 told him about his time limit, the other rangers misinterpreted this information, thinking Zhane was dying. Later after Alpha busted Zhane for taking advantage of them, he was forced to clean the entire Astro Megaship.