I never played RO1, I thought Eremes Guille was from RO2, you barely get any info about this character. You can get a costume called "Eremes style" (His costume), for male and female, and none of them resembles so much RO1Style Assassin Style. It took me some research to understand TurretOvaKil's comment, because in RO2, he saves your life more than once, specially if you're assassin too, but there's a moment when he's told to kill you, but he felt sympathy for you, one of the re-educated orphans who got kidnapped by freyjanity, and goes easy on you. Right before you defeat him, Juliana Russil notices this fact, and stabs a finisher on his back, so she can take you on herself, as he would likely help you if she tried to go for you.
You also get oriented in "abandoned lab", by him., and again Assassin class gets a quest to kill a invisible clone of Eremes Guille in that dungeon. I only played RO2, so Eremes Guille is a good guy who got disoriented and took a couple of wrong and real unlucky choices, in my mind.