So Than will be going along with Red because he knows people will have an issue with fighting and possibly killing humans. And Thanatos... well, he's Death Incarnate and will bear the responsibility to keep others from having to do so. Maybe he can scare some away from having to kill them because he is literally Death and can actually be terrifying as much as he is gentle.

He will also be able to help out with travel within the distortions because he does have his own transgate to use. Healing with his manadrive will be for VoidTreckers only. He will also have Centaur Hearts for anyone who wants to fortify themselves physically for the mission.

However he is also very interested in the two gods of death of this world. He worries they are trapped or something because people aren't allowed to die, and he wants to help bring the world back into a balance as much as he can. If the whole problem can be solved on a godly level to make things right....