Read Avengers Arena.
It's gritty and blood thirsty.
Twenty teen heroes trapped on an island by Arcade until they kill each other.
After 15 issues, Half of them are brutally dead.
Kid Briton was young Brian "Captain Britain" Braddock from an alternate dimension trapped on Earth 616 (or visiting?) enrolled at the Braddock Academy where he was dating a Sociopath and sleeping with a hot blue Atlantean mistress coed.
Brian was an ass, who got what he deserved.