Incognito presence is cast on the mage that cast it (the caster) and EVERYONE else around is subject to the effects now effectively emanating from the mage as it says in the spell, it does not use special target factors as it says in the spell. So by excluding consilium mages Mateus excludes himself the only viable target of the spell and thus despite the spell going off it has no targets.
Their attire might not fit the scene but no one stops to pay them any much mind focused as they are with their own mourning or getting inside, a few others from around the area have also wondered in and a a handful more stand a little awkwardly nearby also not sure if they should be going in or not a wake after all can be a very private and difficult affair.
Mateus begins to cast some spells that ultimately leave him with two spells in his pattern but only the fate spell offering him any boon for his supernal efforts.