Regarding how to gauge the reliability of statements about characters. The answer depends on the person saying it. Let's make a hypothetical example. "The Green Knight is stated in-universe to be invincible. So far, he has taken every single attack thrown at him on the chin and either picked himself off the ground or absolutely tanked it, coming out completely unharmed either way. However, he lives in a low fantasy setting. Is he truly invincible?" A character CAN be upgraded by word of mouth alone. You just have to double check to see by how much, as well as: