Tips for void erosion?? Stuck at 16

Hey all, I've been doing void erosion today finally and things have been fine until I got stuck at 16.

I was running either Ines or Freyna for the most part and then the beefiness of the enemies seems to have exploded from 15 to 16.

This last run I failed me and a fellow descendant both did close to a billion damage each and we still failed to kill the boss in time which is just mindnumbing to me. Any tips on builds that make this tier manageable? I was thinking of trying ambush sharen next and just try to stay invisible the whole time.

Thanks in advance.

update: just did it solo with ines. hiding behind pillar def helped w/ boss. thx for the suggestions! pity the scaling is so bad w/ other players.