Dragon King Darrien has increased magical power beyond what he used to have, his strength and powers were doubled when Lord Orion unlocked Darrien's hidden potential, thus making him a full god. He was also given the Staff of Orion as a parting gift, with it Darrien became an all-powerful being. Nowadays Darrien can do anything, given all the power he has.
He is considered the most powerful being in the Thirteen Realms of the Greebus sector.
Mystic Purple Abilities
Elemental Breath: Fire Breath - Ice Breath - Electric Breath - Water Breath - Earth Breath - Light Breath - Convexity Breath
Magic: Fireball - Triple Flameball - Exploding Fireball - Cometfall - Firestorm - Napalm Strike - The Daybringer Flame - Hail- Snowstorm - Glacier - Avalanche - Ice Beam - Deep Freeze - Shock - Tribolt - Thunderstorm - Drizzle - Riptide - Tsunami - Cyclone - Hurricane - Mudball - Earthquake - Holy - Banish - Meteor - Ultima
Ki Attacks: Aether Blaster (Darrien's version of Final Flash), Aether Bomb (Darrien's spin of Death Ball), Galaxy Crusher
Dark Magic Immunity
Dragon King Abilities
Size Enhancement (Advanced Level)
Basic: Chocobo, Bomb, Ifrit, Shiva, Ramuh, Titan, Elemental Monolith, Jack Frost
Advanced: Lailah, Knights of the Round, Odin, Behemoth, Leviathan, Ziz, Bahamut, Ragadibidoda
Darrien is the leader of the Mystic Purples and one of the Dragon Kings, and is vastly way more powerful than all Mystic Purples, but Malefor potentially rivals his powers.
Harming, Misleading and Trapping
Mystic Purples - While normal dragons can't physically hurt Darrien, with their own strength, Mystic Purples can physically hurt each other. He is considerably stronger than Selena and Baros, however Darrien's power is potentially rivaled by Malefor's but Darrien is ultimately stronger.
Dragonbane - Darrien is more immune to Dragonbane than normal dragons, it can't kill him, but it can slow him down.
The Hulk - As a being of immense strength, The Hulk can bring harm to Darrien but can't kill him.
Thor Odinson - God of Thunder and Prince of Asgard, Thor can damage Darrien.
Elsa - As a powerful mutant, Elsa is powerful to freeze Darrien in ice for a short time.
Banishing or Destroying
Bahamut - As the head Dragon King, and the most powerful dragon in existence, Bahamut can kill Darrien.
The Darkness - As a primordial force, It can kill Darrien.
The Aether Blade - Being powered by the Aether Stone, the blade can kill Darrien.
The Legenday Beasts - Being the most powerful monsters in existence Behemoth, Leviathan, and Ziz can destroy Darrien. Their abilities surpass even archangels.
Death - As literally the bringer of Death, he can kill any being, including Darrien.
Death's Scythe - As the scythe was even able to kill Death, it can therefore kill Darrien.
The Old Gods - As these gods are older than the universe itself, they can drive Darrien mad and outright kill him.
Excalibur - As the most powerful sword in existence, bar none, it can kill Darrien.
Archangels - Being Heaven's most powerful forces, these beings can take Darrien out of the picture. Michael, Raphael, and Gabriel can all kill Darrien.