I've used this before on a similar card but here it is again! Memory Make Magic! It has so many options and I think if correctly applied and with the perfect combo of moves, magic and tactics then this could be without a doubt one of the strongest and coolest magic in their respective universe!
It's hard not to mention Jellals True Heavenly Body Magic as well! This has been one of my favorites since the tower of heaven arc! But that's not all!
Lightning Dragon Slayer Magic/Natsu lightning flame dragon mode! Pretty much any type of magic relating to the control of lightning is pretty freaking bad ass! And the dragon force is also a huge plus in my eyes!! Could you imagine how powerful Laxus would be in Dragon Force mode!!