Luka/Judgement

Seems to be Luka who has joined the angel side... He brings judgement upon those he deems unworthy.

Reflects any Holy attribute attacks and gets 2 actions per turn. Slayer attacks other than Human/Angel slayer deal 90% less damage (10%). Base physical and magical evade of 30%

All of his skills except "All Cancel" are sealed against a solo Luka

Biograph
One of the superbosses in the Labyrinth of Chaos. Descending in a pillar of light, Luka Judgment gazes upon the party. The party is most certainly confused, but prepare for combat.

Upon defeating him, Judgment quips one last sentence before vanishing.

Attacks

 * Tidal Wave - All Foes, Auto Hit, Water Attribute, 3 Turn Cooldown
 * Empty Sky - All Foes, Physical/Wind Attribute, 3 Turn Cooldown
 * Star Scream - All Foes, Auto Hit, Earth/Terra Attribute, 3 Turn Cooldown
 * Judgement - All Foes, Auto Hit, Eternal Damage, Ascension 75%, 3 Turn Cooldown, 16 MP
 * Sword of Heaven's Army - One Foe, Auto Hit, Physical/Holy Attribute, Ascension 10%, 3 Turn Cooldown, 18 MP
 * Daystar - Self Buff, One Turn Null any Attack + counter, Hasted Skill, 6 Turn Cooldown, 20 MP
 * Daystar Counter - One Foe, Auto Hit, Holy Attribute, Ascension 10%
 * Lightning of Judgment - One Foe, Auto Hit, Lightning/Holy Attribute, Ascension/Shock 75%, 3 Turn Cooldown, 18 MP
 * Big Bang - All Foes, Auto Hit, Holy/Eternal Attribute, 3 Turn Cooldown
 * All Cancel - All Foes, Dispel, 5 Turn Cooldown, 6 MP
 * Ilias, Goddess of Creation - All Foes/Self Buff, Auto Hit, Eternal Attribute, Ascension 75%, Gain 100% Crit chance/Accuracy/Physical Evade/Magical Evade for 4 turns, 5 Turn Cooldown, 80 MP

Strategy
Well... this fight is among of the harder fights in Paradox Part 2's LoC for various reasons. Lets address the first issue: Judgment is 100% completely IMMUNE to ALL elemental damage! However, Judgement is still "Weak" to slayer abilities and attacks, but if it isn't Human/Angel slayer (Angel Slayer in particular is something only Corrupted Hero can get without finding the Angel Slayer Gem in the LoC), it does only 10% damage. Judgement can also take damage If the attack has a chaos element with it. There are 2 attacks that any character can learn that have this: Nuclear, a Magic Science skill, and Page 99999 of the End, a Grimoire Skill. These skills are Nuclear damage and Demise damage respectably. Some LoC weapons also have Skill Use:[Skill] that can allow a way to damage judgement.

Second issue, alongside the fact that Judgment takes 2 actions a turn, all but one attack of his is auto hit, and only 2 of his attacks target one person. This means that every turn, no matter what, it is highly likely Judgment will use two AoE instakilling attacks to wipe the front row out. How can you get around this? Well, being an angel, Judgment's skills are mostly holy type attacks, and holy type attacks use mana along side SP (Which enemies completely ignore). Therefore, the number one thing to do is to drain Judgment's mana, to prevent 3 highly dangerous attacks. Those being: Daystar, nothing needing to be said about that, Ilias Goddess of Creation, which is likely to ascension everyone in the party while making it nearly impossible to hit Judgment for 4 turns, and All Cancel, the usually dispel that super bosses carry. Upon draining his mana, Judgment has only 4 possible moves out of 10, which, in a perfect world, would be a 60% chance to waste a turn. However, all of his attacks have at least a 3 turn cooldown, which means eventually he will attack with a non mana using attack. However, since none of his attacks hit more than once, and all of his attacks that inflict ascension cost mana, having everyone use a deflector making move (Makina's Electromagnetic Armor or Summoning Victorious Ceria) means it isn't possible for the user to die, as long as they use it every turn. Then what? Well, either you risk a turn setting up buffs (Like right after he uses one of the attacks that don't need mana), or have a character who can have more than one action a turn. Slimes are good for this, as they can have 3 actions a turn. Or, if you were lucky enough to encounter her, the Queen Mermaid can teach Aqua pentagram (White Magic, 2 Hit Deflector), allowing one member to make deflectors for another.

Unlike his counterpart, Worldbreaker, Judgment is easy to lock down once you drain his mana. Still, until that happens, keep on your toes and keep your mind sharp.

Check here and here for detailed information on all the superbosses and everything you can make use of to defeat them.