力 strong

My REOCCURING dream is so strong, I wake up screaming. With a boner.

力 is basically like sword 〔刀), but the vertical line goes UP OVER THE TOP, making a kind of little 'head'.
So, here's how to tell sword apart from strong:
"I got the STRENGTH to lift the sword UP OVER MY HEAD ."

violence ★★★★☆
暴 (rampage) + 力 (strong) = 暴力 (violence)

violence of person against person.

really grueling effort ★★★★☆
努 (make an effort) + 力 (strong) = 努力 (really grueling effort)

cooperation ★★★☆☆
協 (cooperate) + 力 (strong) = 協力 (cooperation)

the official term for Yakuza. ★★☆☆☆ NP
暴力 (violence) + 団 (group) = 暴力団 (the official term for Yakuza. )