First of all, I'm going to explain how much of Ouroboros' hax could Fugil use on this key. Since this match explicity only has Bahamut, Arshalia won't be using Ouroboros, and thus basically everything Ouroboros has won't be here. Exception to this would be Zero One, which will still be usable due to holding Ouroboros' Sword Device, but Fugil doesn't use Zero One as much as he does with Ouroboros when he only uses Bahamut.
Now for Fugil's abilities:
1. Reload on Fire:
User blog:Ionliosite/Saijaku Muhai no Bahamut: Reload on Fire. Yes, I made a entire blog for it.
2. Chaos Brand and Linker Burst: Exactly what his page says, Chaos Brand is a sword and Linker Burst is magnetism manipulation.
3. Violent Strike: An advanced level of Reload on Fire that allows Fugil to push the ability to the limit and basically stop time.
4. Critical Hit: An special sword technique that allows Fugil to reflect his opponent's attacks by hitting them with Chaos Brand in the right moment. Againts weapons, the whole energy would be reflected to the weapon that made the attack on the first place, normally resulting on said weapon breaking.
5. Quick Draw: Pretty weird ability made to allow Fugil to attack opponents 10x faster than him.
6. Quick Shot: His Instinctive Reaction and Precog, which ar obviously passive and always active.
7. Recoil Burst: Basically draws as much energy as he can on his sword to deal an extremely powerfull slash. Lux, while weakened, used it to one-shot Balzeride, who had absorbed Lux and Krulcifer's power and became much more powerfull than non weakened Lux.
8. End Action: The favourite technique of the brothers, hundreds of consecutive slashes on a very short ammount of time that deal devastating damage, so much that Sacred Eclipse's Low-High regen has a hard time healing.
That's all the main stuff he does.