This power allows you to travel back and forth between hell and the material plane via the 'pathway' command. It takes 30 seconds to shift between planes, and engaging in combat will disrupt your attempt.
Because of your close association with hell, you gain +1% immunity, +2% armour and +1 auto-absorb per rank vs heat damage. In addition, you gain +1 bypass per rank for all heat-based attacks you make (including those of your warbeast, if you have one).
If you also have the Witch Spawn talent, the above bonuses are doubled, and each rank in this power will also give you +10 range, +2 Ascendancy and +1 Power to each of the spells granted by Witch Spawn, as well as increase their duration and stat bonuses by the equivalent of 5 ranks.
If you have access to magic, this power gives you the Hellfire Bolt and Summon Guardian spells. At rank 2 you get Fever (if you also have Witch Spawn). At rank 4 you get Immolate (if you also have Witch Spawn) and Fireblade. At rank 8 you get Resist Energy (heat). At rank 10 you get Fireshield. At rank 15 you get Hellish Armour (if you also have Witch Spawn). At rank 20 you get Hellfire Storm and Drain Heat. At rank 25 you get Dimensional Anchor.
Finally, this power also grants you firebreath (unless you already have a more powerful breath attack) which can be accessed via head commands (type 'h?').