Finewood bows?

Are you using portals?

There is an easy way.
Put a roof over his shrine and a core log low fence lower down.

He can't get in easily, although once he spawned on top of the roof.
His vines, when summoned, just fly up off the ground and get pushed up on to the roof.
You can just stand there shooting him.

https://steamcommunity.com/sharedfiles/filedetails/?id=2594576221