I would think not. The marked bearer is protected against hostile hypnotism. If you read the gnosis carefully you will also see that it does not completely cancel out hypnotism. It only prevents the mark bearer (and the surrounding things) from being manipulated to do things outside of their faith and personal beliefs.
Marked: The first mark of Yahal grants the marked with an enhanced aura, visible to anyone with Auristics, that shines with a brilliant gold radiance. This aura helps protect the marked from magic and other gnosis' that may corrupt or control in a way that would make the marked go against their beliefs and vows to Yahal. This includes defending against hypnotism, chaon, krivas and similar magics. Essentially, this aura prevents the marked from being forced to do anything that would cause harm to themselves or others unless it was something they had already chosen to do on their own. Those within the aura's radius, 10 feet, also benefit from the protection it provides. Those who are already affected by a gnosis or magic that would cause them to harm themselves or others will find these effects (of a strength equal to or less than this first gnosis mark) nullified while they are within the radius. Leaving the aura's radius however will cause the negative effects to return.
^ That is the first mark. From what I understand, or think I understand, about how the new gnosis works is that the more marks you gain from the god the higher amounts of protection you are granted from Hypnotism, etc. In the first mark it also mentions the strength of the magic has to be equal to or less than to cancel out. Note that even Champions of Yahal are still effected by Master level Hypnotism (and its still limited to 'effects that will cause them to harm themselves or others').
This theme is extended to the second mark as well were it is stated:
In addition, the favored can cleanse and effectively nullify the effects of lesser powered chaon effects, hypnotism or fear imparted by the use of krivas (effects that are meant to force the individual to cause harm to themselves or others).
So there is a clear line in where and how the effects are canceled out. At least to my understanding.
Anyways, I do not think having a mark of Ennervism will cancel the gnosis bearers magic. I am no Founder XD and do not know their intentions when reworking the gnosis. But if Im wrong Im sure a Founder will step in and correct me. No biggy. It was an interesting question.