Maybe try the 4th build from this list: ⭐ Top 20 Softcore builds in Grim Dawn (An Opinion)
There’s a save file. It is a Spam Acid Retal Aegis build.
also here [1.1.7.1] Caustic Rebuke: 5:20m Crucible Gladiator, SR 90, 45 seconds Ravager retaliation caster Sentinel [sr+][c+][vid] - #58 by Stupid_Dragon (not the OP but one of the last post)