Gish build for act3

Hi, I'd like to get some recommendations for a gish build for act 3, playing on Custom difficulty with Honor ruleset but without only one save (unmodded, as I want achievements).

I was going for Rivington Rat build but it looks like my specific playthrough is glitched: I am consistently only able to use any special arrow with the first attack of an attack action, and now after finally reaching Rivington and getting Band of the Mystic Scoundrel, I found out that there is a second glitch: I can't cast from scrolls via Quickening Incantation.

I obviously can't continue with the initial plan but I also don't want to scrap the run, so I will need to re-spec and re-tool - but I think I have most of the valuable equipment from acts 1 and 2, so it should be possible. I was thinking either a monk or some gish build (or maybe there is some good monk-based gish build?). Would be grateful for some guidance here.

Other companions are monoclass Tempest Cleric Shadowheart, monoclass evocation wizard Gale and most of the time Thief Rogue 4 / Swords Bard 6+ double-wielding Astarion (I'll swap him out for Wyll, Jaheira or Lae'zel for certain particular quests only).