For Asgore...
Default is a simple "Goodbye." This is the same for X asgore.
For You Know How It Is, he says "I so badly want to say, do you want a cup of tea? But...you know how it is."
For Horror, it always starts with "Heya, Buddy." Then 1 of 4 options for dialog can occur:
"What's with the expression? You look a little bone dry. "
"let me axe you a question."
"i'm axe-cited to meet you."
"What's wrong? You look like you're about to pasta-way."
For Gouki, it says "You are nothing befor