Channeler is a Spirit affinity rare champion from the Skinwalker faction. Channeler has a heal reduction 50% A1 and increases your teams speed on his A3 making his a useful champion. He also has a sturdy defence and HP number making him fairly easy to keep alive.
The strongest areas of the game are likely to be Fire Knight and Agreth the nether spider in the Doom Tower where the heal reduction can be really useful.
Channeler also forms a part of the permanent legendary fusion Rhazin Scarhide, combining with 3 other rares to fuse into an epic champion Bloodfeather.