2-4 nl River decision with KK

[FabledHero]

Okay, this particular player actually bought in at my other table for 250, and worked it up to like 550, he seemed pretty bad, aggressive. He was playing 30/22 And we got down to heads up, and he raised every pot, reraiased etc, eventually teh table filled up, but then he showed up at my other 2-4 table and sat on my left so we had been going at it a bit and this hand comes up. I'm holding KK, I have 394 .00 stack he's built up to like 550 at this table as well, so he's got me covered

zzzkzzz posted the small blind - $2.00
cptgilbert posted the big blind - $4.00
Justitia called - $4.00
FabledHero7 raised - $18.00
zzzkzzz called - $18.00
cptgilbert folded
Justitia called - $18.00

flop- 9h Qc 6h pot (64.00)
FabledHero7 bet - $45.00
zzzkzzz called - $45.00
Justitia folded

Turn- 9h Qc 6h 5d pot (154.00)
zzzkzzz checked
FabledHero7 bet - $99.00
zzzkzzz called - $99.00

River- 9h Qc 6h 5d 7h pot (352.00)
zzzkzzz bet - $200.00
FabledHero7 ?????????

Since he seemed out to try to beat me in some ego war, is your play to call or fold or what? There's 552 in the pot so it's almost 3-1 to me.