[@LuckyBlackCat]

Thanks for the feedback. What do you think would the most appropriate timeframe? I'm personally leaning towards an hour as his maximum time limit, since he was also intended to be kind of a stealthy hero. The boost in speed makes him kind of a ninja when he's not directly fighting, but I had the idea of making him vacillate between a stealth role and having a sonic weapon for stopping villains non-lethally (or riot control). He's going to have a music shtick too. The main reason it was so long was because with his super-speed, I envisioned him as spending long periods in the field with his silence field up, staying out of sight, tailing criminals and eavesdropping on secret meetings and stuff.

However, I didn't want to reduce the time limit without an exact figure from you.