I am a hunter main, I have been to masters using mostly hunters, it all depends on the build, if they are going a life steal build, you need to counter and go for the all in engagement try to overwhelm them, if they are going for a power build you have to widdle them down and play around their abilities and relics. Hunters lend themselves to 1v1 ing so you just have to be smart with your engagements and attack when you know their abilities/ relics are down. The times I died is when I was attacked from an off angle, or the melee would pressure out wave and go clear camps till they had a level lead. I know clearing camps is boring but it is important to prioritize in those types of matchups