“It's just part of the job. My friend Zabba died by your act. That much is true. And at that moment, I could think of nothing but avenging him! But after that, you saved my life... We became friends. That's the truth of it, isn't it?.”
Gerik talking to Saleh

Zabba is a background character mentioned in Gerik and Saleh's A rank support conversation. Zabba was killed by Saleh some time in the past in battle. It seems Zabba was a fellow mercenary and ally of Gerik's.