The Void

The Void is the final location in the story of Fell Seal. It is only accessible if you gathered an Energy Fragment from the Teratoma encounter.

Story Encounter
Level Range: 39-60

This encounter is against The Maw, the Corrupted Souls of 4 Immortals (Primus, Secunda, Sekstus, and Septimus), and 2 Viscerawyrms (depending on your difficulty settings for extra enemies). Completing the encounter requires killing The Maw, but due to its Broodmaster passive ability, it will take reduced damage for each other unit left alive. The Maw will start the encounter by absorbing 200HP from all of its allies to heal itself, and after that it will act similar to how it did in Teratoma. It can inflict debuffs and steal buffs with Dreadmaw, cast Immortal Souls for decent damage, but its regular attack is fairly weak. If the fight gets to at least turn 3, it can use Forsaken One to reduce the HP of all your units to 1 - this isn't so threatening if it's the only enemy remaining, so it's recommended to focus on the Corrupted Souls first.

The Corrupted Souls have the same abilities as their Immortal counterparts (with Sekstus having minor healing and buffing spells), making Primus and Secunda likely the biggest threats. Each Corrupted Soul has a different single elemental weakness at -50, with resistance to most other elements. An important ability to look out for is their counter Shackled soul, which does massive damage to all enemy units upon death unless the Corrupted Soul has (Primus and Septimus) or  (Secunda and Sekstus). You can also bypass this counter by using abilities that specifically bypass counters such as Vangal's Snapback or Mercenary's Flash Strike.

The Viscerawyrms only show up on the Extra or Elite Difficulty settings, and will revive 3 turns after being killed. It's still usually a good idea to take them out since they fairly low defenses and contribute to The Maw's Broodmaster ability. Their attacks and active abilities aren't normally threatening, but they can summon demons if you let them get to 40 MP.