Dark Messiah of Might and Magic

The Assassin

Another weakling at first, the Assassin has several unique abilities. Most importantly, he can sneak about nearly invisibly beneath his cloak. Patience was crucial in our time as Assassins - the cloak was more effective the slower we moved, but as we gained higher levels, it grew stronger and we became extremely difficult to spot. The assassin relies on his instant-kill backstab since he is unarmored, but later in his career, he'll be able to ensnare areas with poison bombs and eventually drop remote-detonated traps.

Assassins can also disguise themselves as the enemy team, and further borrowing the playbook from the Team Fortress' Spy, can feign death. So, give any freshly fallen corpses a stab or two - just to make sure.