Ideas for a 4Link attack to trigger Herald of Purity?

Just looking to make a for fun build, where I 6L herald of purity.

Problem is, I have to be able to kill something fore the sentinels to spawn.

I know that something like Storm Brand works on bosses works (fast hit rate to trigger the sentinel spawn). But for non-rare/bosses, you actually have to kill something (not just hit them).

My first thought was bear trap, which has by default pretty big damage and is physical (as is Herald of Purity). Quickly found out that traps dont trigger on kill effects like those from Heralds. So im back to the drawing board again.

Any thoughts or suggestions?

Could always make it a hybrid build with dom blow.