The mervyl-slaves are led by one of their own in subjugation to the merrevail.
'Now that we have learned a bit of the nest of merrevail in Dannenglor, I think we can take some action against them. Those tokens you collected were made by one of their own.
'I am guessing this particular morvul is a strong brute, and you would do well to remove him if we are to secure Dannenglor against these beasts.
'I am sure he keeps well hidden. Hopefully when you return to Dannenglor, you will find some way to summon him to a confrontation. I do not think he will be able to resist a direct challenge. Be careful, ${PLAYER}; this is sure to be a dreadful challenge.'
The master of the morvul-slaves can be summoned in Dannenglor, north of the Haunted Inn in the Dourstocks.
You should use the merrevail's horn to summon the morvul-guard.
Puiguil can be found in the Haunted Inn in the Dourstocks, south of Dannenglor.
You should return with news of your success to Puiguil.