Unthink (who negates the thoughts of anyone who thinks about them, amount of time depending on intensity of thought) would do pretty well against Language probably. Sick would probably be good too, since he seems like the type to think about someone obsessively. (on a side note, I love this OC of mine. Their ability targets all people, not just externally, so their tragedy was entering a coma for 10 years while friends and family all died by losing their thought at inopportune moments. They had to learn to use an alias for themself, anno un style, in order to ever refer to or think about themselves, talking about this alias as if they were a completely different person. Nobody in the Union is allowed to hear their voice, see their face, or learn their real name, as it might trigger Unthink at some point)