You can make the fight pretty easy if you prepare the area correctly.

https://steamcommunity.com/sharedfiles/filedetails/?id=2556387959

I put a roof in, this forces the roots to get pushed up to the top.

Also use core wood and double fence around the altar. Some fires won't hurt either.

Recently the made his shooty attack much more painful. Put up a hut or two to dodge around and block shots as they get destroyed.

He should go down fast enough with fire arrows and finewood bows.

Had him spawn on the roof once too ha ha
https://steamcommunity.com/sharedfiles/filedetails/?id=2594576221

https://steamcommunity.com/sharedfiles/filedetails/?id=2710324915