One of his skills could have been "Riddle Lockdown". It would allow him to change the color of the keys and the number on keycard doors (however players should still be able to make progress, for example a number 2 keycard door would now require a number one, a number 2 one would require a number 1 or 3 and a number 3 keyboard door could require any and endless possible combinations . The second skill could have allowed the Mayor to have a 4th slot, in which a common item (No keys, keycards, rifles and etc., like a cup or something or his own custom items that have a secret use or just throwing) Generates every 15 - 30 - 45 seconds, allowing the kid player to have enough time to regenerate, but also could be used for a powerful combo. This is based on his ginormous house, riches and profitable position as mayor of Brook Havens. He could have also gotten a cool animation in which he puts his item from his hat (which he wears one). This could have also resulted in a Magician Mayor Skin.
The Third skill, last but not least, could be associated with his dog (which seems like a French bulldog, also makes a skin out of that). He could have just walked around the house have have assigned spots to guard (which sounds like camping), but could easily be bribed with food like milk (not chocolate bar since they are allergic, but add that in the update in which he releases and remove it in the update after that) and other types of food. This food could have also found a great use for the carrot which always spawns in the kitchen in the map - Missing Or Wanted. His love of music (piano) and the garden in his mansion could have brought the two gramophones from Hello Neighbor. This would also be a great distraction for the Guest's skill "Crow sense", which in short allows him to see sound and locate nearby players. The gramophone would also release its sound in an average range so the Crow player doesn't distinguish gramophones from players. (also new skin).