Even though Guardians wield the light of the Traveler, it clear that each has its own pressing issues. Toland and Dredgen Yor are clear examples of this. With Warlock the problem is easier to understand. Osiris - "Warlocks, by their nature, fight a second, internal war. This is the war to understand a universe of secrets— a world that expects Guardians to fight without full knowledge of what they are or what they might hope to achieve...Perhaps what drives a Warlock to madness is truth. " After reading descriptions of hunter armor, I conclude this about Hunters: act like a badass and look good while doing it. Probably the most important thing to a hunter a his own pride. The Grimoire cards say that Dredgen Yor was look up to by others and he later grew to hate that. I suspect something happened to him that made him question his pride as a Hunter. The idea of being a Titan is to believe you are indestructible. "So I ask Wei Ning: what about the Darkness itself? What then? And she says: I'll punch it too." - Pahanin Errata. As a Guardian you must understand that everything has its limits. Wei Ning was killed by Crota. Vell Tarlowe, a Titan, died at the Temple of Crota, he didn't make it inside with Eris. I think part of being a Guardian is trying move forward despite us all having a dark side or needing to understand more about yourself and the world.