thanks zachus,

i managed to get past those guys by just sheer persistence at the time.

But I really meant to ask if there was a way to level up quickly. I will now probably go back,if i saved it, and I want to see if I can level using that guy.

After, I'll be able to tell i this method of levelling works. For now, I can only say that the guy definitely regenerated health because I shot him like 30 times and his health kept going up constantly. In the end I was killing him faster than he was regenerating. In a matter of seconds I acquired the XP for half a level.

I'll check this out and post the result. He was just one of those critters in groups on sentinel island.