A new talent added on the Dragonflight Alpha lets Demonology Warlocks summon a Pit Lord for a short time.

If you pick the new Gul’dan’s Ambition talent as a Demonology Warlock in Dragonflight, you will summon a Pit Lord for 10 seconds after your Nether Portal ends. The Pit Lord’s power is based on how many Soul Shards you’ve spent while Nether Portal was up.

Gul’dan’s Ambition – When Nether Portal ends, you summon a Pit Lord that gains power based on how many Soul Shards were spent, up to 10 shards, while Nether Portal was active. This demon lasts for 10 sec.

The Pit Lord fights for you for 10 seconds after Nether Portal expires.