City of Heroes Positron 2 TF

A Sentinel, it turns out, is a combination of Blaster (ranged damage) primary power pool and Scrapper (being hard to defeat) secondary power pool, making for a rather effective combatant. They're not much for team buffs or healing and if you want enemy debuffs choose Dark Blast or maybe Radiation Emission, because you're not going to get Dark Miasma, but as someone to throw into a fight to blat some bad guys, a Sentinel is a good choice.