[He has to fight off the need to smile a little bit. He knew charms. It was what he was raised on, and he could help Karkat with absolutely no problem.]

I could easily help you out with your charms work. It's really very simple work, Karkat. Why not start out by telling me a situation in which you might need a defensive charm. [He actually smiles, a polite, warm chuckle coming out from the man.]

Say, for instance if someone you aren't interested in is flirting with you.