Crystal Heart Explained (!Spoilers!)
Crystal Heart is the name of the "Quirk" this fanfic's version of Izuku calls his power. It was given to him by the god that transmigrated him from our — real — world to this novel's timeline. It is summarized pretty well by "Izuku's" wish to have "powers from the Final Fantasy Series;" to be specific, Final Fantasy XIII (13) and XV (15).
Crystal Heart classifies as a Mutant type Quirk that places a crystal in Izuku's chest which extends all the way to where a normal human heart should be. It also comes with seven brands etched into various parts of Izuku's body which act as representations of his different "form;" Paradigms, they're called, to keep with the Final Fantasy motif.
The brands are to undergo evolution between Stages 1 to 13 exactly as they did in Final Fantasy 13; the higher the Stage the more abilities within the Paradigm and the stronger said abilities become. Moreover, as the power has been centered around Final Fantasy 13, certain abilities are exclusive to their appropriate Paradigms; meaning, they can't all be used simultaneously and Izuku has to constantly switch to make the most use of his power.
As of Chapter 16:
Izuku has unlocked all 7 brands. In other words, there are no plans for more to spontaneously appear. 6 are Pulse L'cie Brands to match the 6 Paradigms of the Final Fantasy 13 combat system while the last brand is a Sanctum L'cie Brand which represents the level of his summons.
Commando: Manifests as a Pulse L'cie Brand on Izuku's left thigh which initially glows red when switched into. Exclusive to the Commando Paradigm is the boost in physical abilities the brand grants Izuku upon activation along with the ability to materialize weapons from either Final Fantasy 13 or 15; the higher the Stage, the greater the boost in strength and caliber of weapon Izuku may materialize.
At the end of Chapter 11 it is insinuated that Izuku has cultivated the Commando Brand to Stage 8 and has shown the following abilities:
Ruinga: Shoots a point of energy the implodes and annihilates everything within its effective area (1 meter radius).
Blitz: Used with guns, it grants Izuku a burst of speed which he can use to move to more favorable positions and shoot pistols with a firing rate comparable to a sub machine gun.
SUMMON:
Armiger or The Power of Kings: For ten seconds, Izuku can materialize and handle up to ten cold arm weapons (pretty much everything but pistols) telekinetically and teleport.
Weapons created so far:
Blazefire Saber: Lightning's starter gunblade
Engine Sword: Noctis' starter single handed sword
Airstep Sword: Single handed sword from FFXV
Ultima Blade: Engine Sword's final evolution
Total Eclipses: Sazh's Ultimate weapons (FFXIII)
Ravager: Manifests as a Pulse L'cie Brand on Izuku's right thigh which initially glows blue when switched into. Exclusive to the Ravager Paradigm are the abilities to cast offensive elemental spells and teleport and perform warp stikes like Noctis in FFXV; the higher the Stage, the larger the pool and potency of spells Izuku can cast from as well as the further he can teleport.
Chapter 6 had the latest mention of Izuku's Ravager Brand being Stage 6. However, it was January then, when Izuku was taking the Entrance Exams for Recommendation Students, and the school year starts sometime in April. Seeing as he tries to improve all his abilities at the same rate, it can be estimated to currently be around Stage 8.
Izuku has shown the following abilities with his Ravager Paradigm:
Thunder: Shoots a streak of lightning.
Thundara: Summons lightning which explodes onto whatever it strikes and electrocutes everything in range (5 meter radius).
Water: Mentioned but still unused.
Watera: If he can use Thundara, he should be able to use the second level of all offensive spells.
Fire: Shoots a ball of fire capable of instantly incinerating paper to ash — I'd clarify that it can do much more than that, but for obvious reasons, Izuku hasn't used this spell on people.
Fira: If he can use Thundara, he should be able to use the second level of all offensive spells.
Aero: Mentioned but still unused.
Aerora: If he can use Thundara, he should be able to use the second level of all offensive spells.
Blizzard: Mentioned but still unused.
Blizzara: When used near a body of water, Izuku can create a solid ice footpath that can support several people.
SUMMON:
Ramuh's Judgement Bolt: For "actual" summons, I'd rather not explain what they do, since the story speaks for itself; else… I'd be doing this whole writing thing quite badly, huh?
Sentinel: Manifests as a Pulse L'cie Brand on Izuku's nape which initially glows yellow when switched into. Exclusive to the Sentinel Paradigm is the boost in defense the brand grants Izuku upon activation; the higher the Stage, the greater the boost in defense.
For similar reasons to what was written about Izuku's Ravager Brand, his Sentinel Brand can be approximated to be around Stage 8. Izuku has shown the following abilities with his Sentinel Paradigm:
Mediguard: Further boosts Izuku's defense while simultaneously healing him for maximum bullshitery.
Steelguard: At a low Stage, it allowed Izuku to tank a firing squad. Now, he'd probably just be indestructible save for getting punched by All Might or All for One.
SUMMON: Titan's Fury(?) — Not sure if this move even has a name —
Synergist: Manifests as a Pulse L'cie Brand on Izuku's right forearm which initially glows purple when switched into. Exclusive to the Synergist Paradigm is the ability to cast buffing spells; the higher the Stage, the greater the potency and variety of spells Izuku can cast from.
For similar reasons to what was written about Izuku's Ravager Brand, his Synergist Brand can be approximated to be around Stage 8. Izuku has shown the following abilities with his Synergist Paradigm:
Bravery: Buffs physical abilities.
Bravera: Buffs physical abilities to insane levels.
Protect: Buffs physical defense.
Protectra: Buffs physical defense to ludicrous levels.
Faith: Raises Offensive Spell casting potency, and maybe the Quirks of other people — we'll see.
Faithra: Raises Offensive Spell casting potency, and maybe the Quirks of other people, to reality-questioning levels.
Shell: Raises Spell/Quirk resistance (like elemental resistance and whatnot).
Shellra: Raises Spell/Quirk resistance to insufferable levels.
Haste: Buffs speed.
Veil: Raises resistance to status ailments like getting burned, frostbite, stunned by electrocution, etc…
Barfire: Raises resistance to fire specifically.
Barwater: Raises resistance to water specifically.
Barthunder: Raises resistance to lightning and electricity specifically.
Barfrost: Raises resistance to ice specifically.
Enfire: Those buffed by this spell get fire added to all their attacks.
Enwater: Those buffed by this spell get water added to all their attacks.
Enthunder: Those buffed by this spell get thunder added to all their attacks.
Enfrost: Those buffed by this spell get ice added to all their attacks.
Boon: Allows Izuku to refresh the time limit for all the buffs affecting a person by casting a single additional buff.
SUMMON: Unknown
It should be noted that Izuku can buff people other than himself for twenty minutes a piece (at the very minimum), so… This is arguably his most overpowered Paradigm.
Saboteur: Manifests as a Pulse L'cie Brand on Izuku's left forearm which initially glows grey when switched into. Exclusive to the Saboteur Paradigm is the ability to cast debuffing spells; the higher the Stage, the greater the potency, chance of success, and variety of spells Izuku can cast from.
For similar reasons to what was written about Izuku's Ravager Brand, his Saboteur Brand can be approximated to be around Stage 8. Izuku has shown the following abilities with his Saboteur Paradigm:
Daze: Stunlocks a single target if successful. Rate of recovery is dependent on the personal overall strength of targets hit.
Dazega: Stunlocks all targets successfully hit within Izuku's line of sight.
Pain: Completely immobilizes a single target if successful. Rate of recovery is dependent on the physical power of targets hit relative to Izuku.
Painga: Completely immobilizes all targets successfully hit within Izuku's line of sight.
Deprotect: Debuffs physical defense.
Deshell: Debuffs Spell/Quirk defense.
Slow: Debuffs speed.
Slowga: Debuffs speed of all targets successfully hit within Izuku's line of sight.
Jinx: The Saboteur equivalent of Boon to Synergist. Successfully casting a debuff will refresh the time limit for all debuffs on a person.
SUMMON: Unknown
It should be noted that along with Brand Stage, the strength of a person relative to Izuku plays a part in the success rate of being hit by debuffs. Kind of like a bully, this Paradigm works best against people already weaker than Izuku…
Medic: Manifests as a Pulse L'cie Brand on Izuku's chest which initially glows green when switched into. Exclusive to the Medic Paradigm is the ability to cast healing spells; the higher the Stage, the greater the potency and variety of spells Izuku can cast from.
As of Chapter 16, Izuku's Medic Brand is his most developed at Stage 9. Izuku has shown the following abilities with his Medic Paradigm:
Cure: Shoots a green light that heals minor injuries instantly. Mild to severe injuries require several casts to fully heal.
Cura: Shoots a green light that heals all but fatal injuries in a two to three casts.
Curasa: Shoots a green light that heals proportional to the amount of damage the target has sustained. The more damage a person has sustained the more they will heal from being hit by this spell.
Raise: Heals and awakens unconscious people. Might be able to do more later on in the story, so to give context, this is a spell's equivalent of a phoenix down or senzu bean. It was unlocked at Stage 9 so… yeah, it has the potential to be overpowered to hell and back.
SUMMON: Unknown
