A recent version of the official Roblox description advertised Deimos as a new Legendary style. The same game has also shown Surgeon in another recent update snapshot, so the headline may rotate. Confirm the creator drowningsome and Place ID 13621938427, then check the current in-game style menu for availability.
The developer says all fighting styles are intended to be viable and that rarer ones are mainly cooler. Legendary rarity alone does not establish a win rate, damage number or best matchup. If you obtain Deimos, practice light and heavy attack timing, blocking and dash recovery against several opponents before drawing conclusions.
Older drafts of this guide described a Terror Bar, Monstrosity Mode, Bleed, exact ultimate damage and drop rates as settled facts. Those mechanics were not confirmed in the official description we could check. Rather than repeat unverified numbers, this guide recommends checking the game's current move description and testing abilities in a match. For controls and general style selection, see the fighting styles guide.