I don't know if I am any help but,
I depict GMT in three ways in my sessions, depending on who is talking to him.
1) Not-Shadow lodge members - for them, GMT is scarred and sometimes grumpy, but always willing to share more information than VC give them for their missions - for a price ofcourse, cause he needs to make a living. He always talks about cooperation, about helping each other and throws small drops of poison in minds of Pathfinders, about decemvirate and his practices with pathfinders and aspecially artefacts. Cause GMT wants all artefacts of PFS to be used for greater good, not to just lock them from the world's reach. To help Pathfinders and other people - and he has a reason. His scars, curable only by powerful artifact stored in the Society's vaults.
2) Shadow Lodge members - for them, GMT is a strong politician, who makes his moves ahead of others, thinks in a big picture and wants more for his members. But he needs to go over dead bodies sometimes. But that's OK, cause afterall, he does nothing worse than the Decemvirate does and he is always grateful for everything his members do for him. He had to get rid of Spider, cause he/she sent RedMantis Assassins on him, he had to stay in the shadows, cause his face is scarred because of the job he did for Decemvirate and Decemvirate wasnt grateful, they didn't heal his wounds, nor cured his curse. They threw him in the shadow. He is victim. Sometimes angry and really powerful, but victim - and wants just good things for us, doesn't he?
3) In sharp situtations - in a really dense situations, GMT reveals his true self, not only burned and scarred on the outside, but burning and full of hatred inside. He just uses his "mask of victim" to convince others to do a job that's needed to be done. He is like a plague - slow, nearly invisible, but strikes when the enemy is weak and kills him in one hit. And he will use anybody for his cause - to put decemvirate to his knees and take-over the society. He just doesnt care about others. He sacrificed so many, he can't count. He worked with spider sometimes, he works with AC, if he needs - he just uses his web to overtake it all. Only sad thing, for him, it takes so long. But he is patient, wounded, angry, but patient.
