Hero Siege Season 10 Overview

Season 10 is the Ebontharn season. Its headline change is a free Act 9, reached after defeating Odin at the end of Act 8, plus a large progression reset around the Normal -> Nightmare -> Hell -> Inferno flow.

The most important returning-player change is that Normal is now the only difficulty where you run the full Acts 1-9 campaign. After Normal is completed, Nightmare keeps the Normal waypoints, Nightmare now behaves like the old Hell 1 tier, and Hell moves much closer to late-game scaling.

Ether progression is much more visible in Season 10: the official notes add more Ether and Incarnation nodes, patch notes say Ether quest progress is visible in the pause-menu Quest Log on Hell+, and current developer-announcement mirrors report base Ether Points at level 100.

The official Steam launch announcement describes Season 10 as Ebontharn, a major update with Act 9, new chase zones, three new Uber fights, a new seasonal Abyssal Chest, and a broad list of item, class, monster, and system changes.

The progression rewrite is the piece that most directly affects guides. Season 10 makes the Acts a Normal-difficulty campaign path, then shifts later difficulties toward farming, Ether, Incarnation, and endgame progression instead of repeating the full campaign route.

Act 9 is Ebontharn, the new free campaign act added in Season 10. Official notes place it after Odin in Act 8 and describe it as the culmination point before the post-Normal progression loop.

Community walkthroughs currently report that Act 9 ends with Cthulhu in the Abyssal Realm and that clearing that Normal route is the practical Nightmare unlock path. Treat exact NPC names and objective sequence as community-reported until checked in-game.