Before beginning, I will list my important observations regarding Baby Reversion:
-Baby Reversion is NOT removed by debuff removal, although the game lists it as a debuff. Artifact monsters ARE affected by this debuff and will lose their turn! Artifacts are NOT affected.
-Baby Reversion will prevent AOEs from hitting the monster with the debuff.
-If Baby Reversion hits a monster with Skill Mirror, the monster will still reflect the attack, despite having been turned into a baby.
-Evasion blocks Baby Reversion, and Dodge Area will block AOE Baby Reversion, even from the Baby Reversion that happens as a side effect of one of Kronx's skills(Tralfalmadorian).
-There is a Recently Reversed buff, just like Recently Denied buffs.
-Baby Reversion counts as a deny effect, and as such will not affect Control Immune monsters.
-If a monster with Taunt or Mega Taunt gets affected by Baby Reversion, they cannot redirect attacks.

Hello everyone and welcome to my 261st analysis, this time featuring Kronx.
Overview: Sharing the same Base Speed as the powerful Warmaster Sherezar, Kronx is a very unorthodox denier. Her two deny methods are Time Stop and Baby Reversion, the latter of which is somewhat counterproductive since you can't really make use of the deny turn to harm enemies, but the effect is nevertheless strong. Furthermore, not even allies can get rid of it, and from the details of Baby Reversion above, you'll see that it's a deadly weapon to ruin Taunt - Dodge Area cores, because unlike Trait Disable, Baby Reversion cannot be cured. Kronx's Trait protects her from CD Activation, a strong deny effect, and later gives her Tough to face other deny effects. You can use Kronx as just a very fast denier, but with the correct teammates, she can be so much more.

Builds:
Monsters that have access to Group 4 skills will have a slightly different build path. I will list the most viable builds for each Rank since some moves in Group 4 are pivotal to some sets' success. The monster's role will likely remain the same, however, so this won't be exhaustingly long as I won't repeat the same things.

Rank 0
Moves:
-Time Freeze
-Kids Like You
-Time to Switch/You Have Misbehaved/Time Law
-You Have Misbehaved/Time Law
Runes: 3 Speed
Mutant Rune options: Speed&Life
Relics: Banners and Traps

Build Explanation:
Time Freeze is Kronx's safest AOE deny at this point, applying Time Stop which no monster is immune to. Kids Like You makes enemies lose their turns and be Burned, but you can't hit them during that time. Time to Switch applies a random Torture to all enemies and a random buff to all allies, which can be crucial. Lastly, You Have Misbehaved applies great Torture pressure to its target and applies Baby Reversion to it, while Time Law is a single target Time Stop.
3 Speed with Life Mutations is the standard for any denier.

Rank 1: Kronx learns "Sudden Heart Stop" at this level, a single target attack that removes buffs from its target and applies Time Stop to it, then gives Kronx an extra turn. Her Trait also evolves to include Tough.
Moves:
-Time Freeze
-Kids Like You
-Time to Switch/You Have Misbehaved/Time Law
-Sudden Heart Stop
Runes and Mutant Runes are the same as given above.

Build Explanation:
Sudden Heart Stop is an immensely powerful single target deny attack that helps Kronx defeat Dodge Area monsters, and also deny an enemy without losing any momentum. You can still run one of the other 2 deny moves over Time to Switch as well, to get more denies.
Any Hardened variant is incredible to have, and Tough is a good way of countering debuffs that come your way.

Rank 2: Kronx learns "Hyperbolic Time Chamber" at this level, a move that gives an ally Triple Damage and Kronx an extra turn, but applies Baby Reversion to its target.
-Time Freeze
-Kids Like You
-Hyperbolic Time Chamber
-Sudden Heart Stop
Runes and Mutant Runes are the same as given above.

Build Explanation:
Kronx's moveset allows her to use Hyperbolic Time Chamber without many consequences, since it costs her no momentum and it puts great pressure on the enemy to somehow stop the Super Saiyan target. You can even pair her up with Control Immune monsters to get the buff for absolutely free.

Rank 3: Kronx learns "Death is Your Fate" at this level, an AOE that applies a 3-Turn Death Counter, Stamina Leak and Baby Reversion to all enemies. Her Trait also evolves to include SC: Trait Protection.
Moves:
-Time Freeze
-Death is Your Fate
-Hyperbolic Time Chamber/Kids Like You
-Sudden Heart Stop
Runes and Mutant Runes are the same as given above.

Build Explanation:
This AOE is a strict upgrade on Kids Like You, but said move can still be used over Hyperbolic Time Chamber to kill all enemies before they get to do anything, by denying them 3 turns in a row. Dodge Area monsters can counter this, however.
This is an unnecessary SC, since moves that disable traits usually come with buff removal first. Some moves like Draghar's Essence Devour can be countered with this, but it's rare and you're not protecting some crucial part of your combo either, it's just Tough and CD Protection.

Rank 4: Kronx learns "Tralfalmadorian" at this level, an AOE Mega Time Stop that applies Regeneration and Baby Reversion to all allies.
Moves:
-Tralfalmadorian
-Death is Your Fate
-Hyperbolic Time Chamber
-Sudden Heart Stop
Runes and Mutant Runes are the same as given above.

Build Explanation:
With Tralfalmadorian, the Death Counter combo with Death is Your Fate is much smoother, as Tralfalmadorian acts as a 2 turn deny while Death is Your Fate is already a deny on its own. Since it applies an AOE Baby Reversion to your team, you can work around this by giving her specific teammates.

Teammate Options: Baby Reversion, as stated before, is countered by Evasion and Control Immunity and its AOE is also countered by Dodge Area. Therefore, you can use monsters with these to not feel recoil. Warmaster Elvira is a perfect ally that renders Tralfalmadorian and Hyperbolic Time Chamber's side effects null, and you can use allies such as Wyrmlad and Hornet to freely use Tralfalmadorian without much worry for your teammates. With Kronx, you can use moves that would cost too much momentum for free, like moves that just boost damage but do nothing else - for example, Ugluk's Battering Lizard. Since you can't hit enemies anyway, you might as well give them a surprise when they revert back to adults. For more Teammate options, check out this article.

Countering Kronx: Be aware of the fact that Tralfalmadorian cannot be reflected back with Skill Mirror, since Kronx's allies will have Baby Reversion applied to them, negating the Mega Time Stop. Control Immunity will block Baby Reversion. For more Counter options, check out this article.