The loot table for troops in Hellcrag event chests is expected to look like this:
| Chance | Amount | Troop |
|---|---|---|
| 0.11% | 1 | The Colossus, Tourmaline |
| 3.2% | 1 | Czernobog, Xenith |
| 12% | 1 | Adakite, Chalcedony, Eternal Sentinel, Herald of Torpor, Morganite |
| 21.6% | 1 | Craghound, Nabassu, Petrahulk, Stone Panther |
| 21.6% | 2 | Petrified Golem, Stone Mefyt, Stone Zombie |
| 21.49% | 3 | Hellstone Gate |
Unfortunately, event chests have a tendency to be misconfigured, either entirely missing specific mythic troops or containing them at significantly lower than advertised odds. There is no way to know this ahead of spending, and no way to get any kind of refund. If you plan to open event chests, wait till the weekend for the community to find irregularities, this significantly reduces your risk of getting burned.