So I saw that every herald you kill in a game adds a tier to it up to tier 5

If I use shards to terrorize acts does it carry over between acts if say I kill 4 herald in act 1 and another in act 5?

Do the herald reset every half hour when the tz changes?

Herald tiers only reset between games, not acts or TZ.

Any herald after tier 5 is another tier 5