There is only one Odin. Odin shared his power with Raogrimm to sate his rage, thus turning him into the Shadow Lord. This doesn't mean that Odin is allied with the Shadow Lord, simply that he shared his power with someone capable of bringing death and destruction to the world. In the alternate WotG timeline, Lillith got her power from Odin as well, the very same Odin that granted power to the Shadow Lord. Again, he saw someone capable of bringing death and destruction to the world, and awarded her with dark powers, and the ability to call forth demons. He could care less who carries his power, only that the end result is a world filled with darkness and destruction.