Assassin Wot is a Marauder by enemy type. He will lob more than a few grenades at you and fire at you a good bit.
Southpaw Steam and Power:
Wot makes his appearance with a Badass Psycho. The Psycho can be led away. They do make a good combination as Wot gives ranged support to the melee based Psycho. Kill him with the Pistol is not too hard as a optional objective. Just be sure that you weaken him with something stronger first and finish him with the pistol.
Wot appears without any of his support. He can jump very high and moves around a good bit. Pay attention to where he is so you can have some cover from him. He is something of a break after taking on Rouf.
Head shots and fire