Guide souls towards the afterlife
Create paths for souls with beacons of light, to allow those who have departed the mortal realm to transition onto whatever fate awaits them.
Repel the invasions
Defend magical planes from corrupted invaders with powerful towers. Enchant these defensive structures with spells that petrify enemies, trap souls, or summon elementals of fire. Or cast rituals that bind hollowed souls to the Psychopomp's will, exploding in a ball of arcane fire.
Seal the planes
The ancient seals that stabilise the astral planes have broken yet again, leeching all manner of corrupted beasts and entities that seek to destroy all who inhabit the astral sea. The Psychopomp must hold off the invasions long enough to seal these planes and prepare souls to freely transition between realms once more.