To be honest orks are just better versions of humans, but a troll would be more evenly matched against a demon.
And actually I take back my statement about Molkarg he would probably be just a bit worse than Ling you know who the most powerful being in Terra is?
Shedanaran the Eternal Liberator, Ling may be a demon emperor but Shedanaran is Lings overlord.
Technically.