Defeating her is one of the most difficult fights, as there is no "ruthless" way to kill her with tricks. She attacks with her Gorgonite 2h sword on crush, which is fairly accurate. She sometimes teleports with a call of "Catch me if you can!" and casts some magic. If she is attacked quickly after she teleports the player may do lots of damage. She wears a Gorgonite platebody and Gorgonite plateskirt, but does not appear to have as much defence as the armour would suggest.
After Evolution of Combat however, Kay becomes extremely easy to defeat. Additionally, a damage over time effect (such as Dismember) will interrupt her teleport attack.
When defeated, The Forgotten Warrior decides her fate depending on the warrior's ruthlessness. She could be killed outright, tortured to death or spared, making her the only one of the party of four to have a chance of surviving the Warrior's vengeance. The Forgotten Warrior believes that she murdered a group of children although it is later shown to be a hallucination.
The name "Kay Thanxby" is a reference to "Kthxbai" (Ok, thanks, bye). Like the other characters in this Saga, she lives up to this name, though instead of using it during dialogue she references it with her teleportation trick.
Kay Thanxby has exactly 80 Attack, as she can wield a Gorgonite weapon but cannot use Meteor Strike, which requires 81 Attack. She also has at least 80 Defence to wear Gorgonite armour, but less than 3 Strength as she cannot use Kick.