Hi!!
I know I haven't made Seraphiel's power's too obvious, so I will use this as an opportunity to explain a bit about them and where they come from,
First off Seraphiel is the angel of silence, and for those of you who don't know for silence… true silence not just like when someone farts in the car… you need the medium for sound to be interrupted or not exist, for instance in space there are not enough particles around for sound to travel, so there is true silence. Therefore, an angel that can control silence it stands to reason that they are able to change the vibrations of particles or eliminate the medium needed for sound waves to travel, and this gives you a lot more than just a hardcore way of saying shhh
For instance plasma the fourth state of matter can be made by superheating gas, and heat or lack thereof is just the speed at which particles vibrate, therefore by vibrating the particles in a hand would slowly burn it and superheating it further would turn it and the surrounding air into plasma, similar to what the sun is made from.
As for the Seraphiel from the bible and other related texts he is referred to as the angel of silence but also teaches people to sing in a way of praying to god, in this he is able to create the sound or superheat particles by singing hymns (religious songs) similarly the Seraphiel in the bible is tall, like seven heavens tall… now I'm not sure how big heaven is however that's a lot taller than Mahon, which is why when he completely takes over (Chapter 13) it rips Mahon to shreds, Similarly Seraphiel is the ruler of mercury, the closest planet to the sun.
Now as for Seraphiel himself I see him as a separate person to Mahon, however he is still very much affected by Mahon
However Mahon is not affected by Seraphiel's emotions and connections which is why Mahon… punched god.
Thank you for reading.