Having himself kidnapped wasn't because he was itching for a fight or looking to loosen up.
There was a deeper reason, he wanted to further enhance his abilities.
The two times he was on the brink of losing control, he had demonstrated greater strength than in his normal state, so he wanted to master that state.
But in those two instances, he was nearly out of control. He wanted strength, but not at the cost of losing control, hence he concocted this unconventional solution.
He sought ordinary people to torment him, to actively make himself angry and get hurt, yet without completely losing himself.
He believed that what made him stronger was not madness, but a tipping point between sanity and insanity.
That's why he deliberately weakened himself and orchestrated this kidnapping.
Of course, a normal person wouldn't think this way.
"Laugh? Laugh your head off!"