His Magic is Aethereal Fire Magic which is why there is fire everywhere, since he literally kills almost every single Vanaham member there ever was. However it isn’t fully visible since the flames are to realistically represent what would happen if Magical fire is gone from a heatable source which shows why you can’t see the Aether magic in the backround and foreground, however the flame coming from Sage White’s eye is Aethereal Fire Evolution 3.
Anyhow what ended up in the massacre was Sage’s bounty going from 5 million drachma to 15 million drachma, the Grand Navy keeping high tabs on Sage, Vanaham Pirate’s destroyed and gone, a War Seas island that has been ablaze, and many pirates fearing Sage.