As you continue to progress with Season of the Malignant, you will eventually reach Season Journey Slayer, which comes after Chapter 4.
This makes things a bit more challenging as Nightmare Dungeons and the Helltide are involved with your progression requirements.
It is expected that you will be around Level 50 or higher to get past this set of challenges and will need to complete some in World Tier 3.
Chapter 5 (Slayer) Season Journey Objectives
To complete Season Journey Slayer, you will have to complete the majority of the following challenges during the Season of the Malignant:
1) Wrath’s Beating Heart
Acquire a Wrathful Malignant Heart.
2) The Depths of Fear
Use 5 Nightmare Sigils to empower Dungeons and complete them.
3) A Boon in the Tide
Open a Tortured Gift of any type during the Helltide Event.
Craft 2 Nightmare Sigils at the Occultist
5) Cut the First Ear
Kill another player in PVP.
6) Prophecy Master
7) Lingering Wrath
Defeat the Echo of Varshan after completing the Seasonal Storyline.
8) The Paragon’s Path
Unlock 15 Paragon nodes after you have reached Level 50.
9) Restored Glory
Upgrade 2 items to Level 5 at the Blacksmith or Jeweler.
10) Exceeded Potential
Improve 1 Paragon Glyph to Rank 4 after completing Nightmare Dungeons.
Slayer Season Journey Rewards
To complete Season Journey Slayer, you will need to do at least 9 out of 11 of the objectives and will be rewarded with the following:
- Epic Favor
- Fifth Journey Cache
- Craven Aspect
You will need to start delving into Nightmare Dungeons to complete the Slayer Season Journey challenges which require you to be in World Tier 3.
In World Tier 3, Nightmare Sigils can be obtained from the Tree of Whispers rewards while the Helltide Event occurs in this tier as well.
This means that you will need to have completed the Cathedral of Light Dungeon, which allows you to change to World Tier 3.