Didn't Jade say 'fuckass' four times total? I remember that. Sorry, I don't have links.

I can’t remember for sure and searching every pesterlog is time consuming, but to my knowledge the word fuckass has only been used 4 times total:

• John said it to Karkat once (jokingly)
• Karkat said it to Jade once (for the record, he was calling himself a fuckass, not Jade)
• Jade said it twice to Karkat (2 conversations, said once in each)

Fact checking things that were said in pesterlogs is difficult.  I remember seeing a chart or something that showed the actual use of words that the fandom has overused (gog, jegus, fuckass, etc.), but I haven’t seen it recently.