if i can't kill a herald is it possible for another to spawn without killing the one that is immune to me?

Yup
It will be same lvl tho

ok thanks just wondering if i was wasting terrorizing the whole act. got my third lvl pretty quick but after i left him i've gone through half the act with nothing

Spend some FG I got a sunder for ya

haha maybe.

I killed the tier 2 herald then terrorized all of act1. i worked my way from start clearing all enemies, boss/champion/normal . encountered tier 3 herald in underground passage lvl1 immune and couldn't kill him. kept going through act1 and herald message never came back, never saw another one all the way through to andy.

RNG is a bad b*tch and thats why we like her