Southbound and siege ballista problem

Southbound's "Your Hits can only Kill Frozen Enemies" seems to be incorrectly applied to my siege ballistas. Either this is a bug or there are bugs for herald of thunder, herald and ice and other skills referring to "you" as those are not proccing from my siege ballistas.

Sorry for not being more clear. Yes my issue is that Southbound is applying to my siege ballistas, preventing them from killing enemies unless I crit and freeze them.

Sounds like a bug to me. Why would equipment that refers to you (such as Southbound) apply to a siege ballistas but a herald which also refers to you in its proc (eg herald of thunder - "If you kill a shocked enemy, lightning bolts will strike enemies around you for a short duration") not apply to a siege ballista?

It's exactly like Raye explained. The Siege Ballista has all your stats, but it doesn't actually have your skills. So it can inherit the stats from the HoT buff, including the chance to proc HoT from the buff, but it can't actually proc HoT because it doesn't have the skill itself. Same reason CoC and Curse on hit don't work with totems.

Also, if it could somehow proc HoT, it would be centred around the totem, not you.