Some ideas for mid-ranks, most of which are niche:

1. Thug thief. Trip non-melee classes to death w/ cheap shot. For melee classes either flee/knife or, if you also have bind legs, bind legs then backstab. If you don't want to deal with preps then go Battle.

2. Bashing warrior or orc. Down side: less scary when you can't bash.

3. Assassin. Can't flee from an assassinate. Sucks when target can see you, or if target is smart enough to make themselves hard to stalk. Also assassinate is frustrating at low skill %.

4. Sleep-spam Anti-Paladin. Duergar for resist_thief and resist_assassin. Find and horde non-sleek wands. Vault. Most people don't keep the necessary preps and gold on hand to survive a full sleep+maledict. This is the Shaapa template.

5. Sleep-spam Necromancer. Human for the better range. Same advice as the anti-paladin re: wands. Find and use plague if possible to augment your built-in spells. Gravesight to locate corpse after they teleport away (blind) and die.

6. Ranger. Either cloud giant for bearcharge spam, or play like a thief and ambush wounded people. Target can't flee if he dies to your ambush. Obviously limited to certain areas. Down side: people will just avoid them when you're online. Mitigating factor: they may not have a way to tell you're online. Go Outlander for extra mojo.

7. Jakhu, i.e. level sitting uncaballed evil transmuter. Human.