subject line says it all…
Chthonics and Bloodsworn both deal heavily in Chaos damage. Some Vitality damage in there too, I believe, though I don’t think it’s as prevalent as Chaos (I could be wrong). Occasionally some Chthonics will deal some Acid/Poison damage (Gorgers’ vomit attack), a decent number of them will deal fire damage (Shar’zul is most notable here, though I believe Voidfiend Incinerators deal heavily in fire as well). Physical is surprisingly prevalent across a number of different Chthonic monster archetypes - Ravagers/Shaleborn/etc. deal a lot of physical damage with their stabbing attacks, IIRC, and pretty much any Chthonic that melees you will be doing SOME degree of physical damage I believe.
Chaos, OK thanks.