After completing the trials of the Temen Ni Gru and defeating his father Sparda. Vergil obtained a level of power that not even Mundus had. All demons who see the symbol that Vergil wears know to bow before him and do not dare to challange. Due to the last king to wear the symbol time is unknown not many know the symbol immediatly but the anciet lesser demons seem to know the symbol at first sight.
Vergil clothing changed back to his DMC 5 look rocking a black and purple color scheme with glowing edges and patterns with the symbol printed on the back of his robe while also getting shoulder plates formed from Gilgamesh (Not the Devil Arm. DMC has it recorded as a metal from the bedrock of the Underworld as well)
Vergil's face changed to a grey color while also revealing cracks in his skin with yellow eyes and the mark on his face(Refrer to very first image to better see the cracks.) Vergil also got a new pair of horns attached to his head as a new crown thus also made from Gilgamesh metal.
Nothing diffrent with the devil clone other than a color makeover.
Vergil Sin Devil form also changed to match his color scheme. Black scales and purple energy.
The Yamato has returned to a more normal form. It's design is diffrent from the original design with a longer handle and a new sheath and tusba. The blade itself has changes to having a yellow and purple strobe pattern as well.
Beowulf got simple changes like the clone all it got was a color makeover
The Mirage edge got a new look too. It got a more sharp design and has a eye on it for some reason.
Credit: https://www.nexusmods.com/devilmaycry5/mods/1229