This is one of my favorite Competi-Fun decks I've made this year. I've always liked Dark Magician, so I figured why not make a new deck for him this year.

Monsters: 18
Dark Magician x3
Gemini Elf x2
Genex Controller x3
Black Luster Soldier - Envoy of the Beginning x1
Effect Veiler x2
Elemental Hero Prisma x3
Rescue Rabbit x2
Skilled Dark Magician x2

Spells: 15
Dark Hole x1
Dark Magic Attack x2
Dark Magic Curtain x2
Heavy Storm x1
Monster Reborn x1
Mystical Space Typhoon x2
Pot of Avarice x1
Pot of Duality x3
White Elephant's Gift x1
Wonder Wand x1

Traps: 7
Mirror Force x1
Champion's Vigilance x2
Solemn Judgment x1
Solemn Warning x2
Torrential Tribute x1

Extra Deck: 15
Dark Paladin x2
Ally of Justice Catastor x1
Arcanite Magician x3
Black Rose Dragon x2
Brionac, Dragon of the Ice Barrier x1
Leviair the Sea Dragon x1
Number 11; Big Eye x1
Number 16: Shock Ruler Conqueror of Colors x1
Number 30: Acid Golem the Destruction x1
Steelswarm Roach x2

i could say add ancient rules but that depens on how often do you draw dark magician,swing of memories could help here since you have a good number of normal monsters so you could use swing of memories for synch/xyz,by the combo you pull with prisma,you could add a dark erradicator warlock,and maybe,in turn, sorcerer of dark magic,chaos sorcerer could be good there,and could combo with resonance device,for easy rank 4/6/7 xyz summon,and in turn,addtion chaos would allow you for locomotion r-genex
thats all i can think of now,since im a little tired,i'll check later which cards could you replace with the ones i mentiones,if you like my ideas of course