“So this is Takatou’s one weakness...or at least that’s what it looks like, but it’s not really a weakness, is it?” Tomochika said, watching Yogiri sleeping peacefully on the couch.

“Indeed. If you shake him, he will wake as usual, and even while asleep, he will automatically use his power to defend himself.”

According to Yogiri, using his power tired him out. That said, he didn’t have a real limit to it. He could use his power as much as he liked. When exhausted, he had a tendency to sleep for days, but he would wake up normally if you tried to wake him, so it wasn’t much of a problem.

-Volume 13 page 93