I BEAT KARL WITH ONE SQUAD! Well, in JP.

...YES, it warranted an update.

Karl was insane, let me tell you that. I keep on dying at Blue Execution in my Global file, but in my JP file...

I beat him the first time. With one squad.

I came into the battle with 3 squads, the first one being the squad THE Ushi-sensei suggested (he suggested using a Grah helper, but I didn't have a Grah helper, so...yeah). The three squads are...

Team 1: Reeze 5* (leader, B), Tesla (G), Elimo 5* (A), Alyut 6* (A), Lodin 6* (L), Lira 6* (helper, B)
Team 2: Kushra (leader, L), Elulu 5* (L), May 3* (B), Emilia 5* (L), Falma 5* (A), Eze 6* (helper, G)
Team 3: Aem 5* (Leader, A), Lemia 5* (B), Zephyr 5* (B), Duel GX II (L), Lance 5* (G), Il and Mina 5* (helper, A)

I only used team 1. I brought Fujin Elixir, Divine Light, High Cure, Revive, and Thunder Seal (it was insurance in case my first team died). Tesla and Reeze died at Blue Execution. Lira died near the end, and I revived her to make sure Karl dies quickly.

In hindsight I could've won even without reviving Lira.

So, the stats of my first squad...

Hail Mech Reeze (Leader, B)
Level: 77/80
LS: Nullifies all status ailments
Sphere: Sacred Jewel
Stats (HP/ATK/DEF/REC): 6189/2058/1315/1413
BB: 10 combo water AOE, chance of paralysis (level 2)

Ice Tower Tesla (G)
Level: 54/80
Sphere: Goddess Seal
Stats: 5066/1157/1922/883
BB: Halves damage taken for 1 turn (level 2)

Genius Elimo (A)
Level: 80/80
Sphere: Flesh Armor, Poison Shiv (w/Sphere Frog)
Stats: 5263/1003/1674/1721 (light stat imp buff)
BB: Greatly recovers HP, gives DEF buff for 3 turns (level 2)

Divine Light Alyut (A)
Level: 71/100
Sphere: Beast Blade
Stats: 6273/1906/1795/1644 (light stat imp buff)
BB: 11 combo light AOE, chance of injury (level 10)
SBB: 14 combo light AOE, BB gauge refill & HP regen for 3 turns (level 7)

Empyreal Drake Lodin (L)
Level: 76/100
Sphere: Medulla Gem, Skill Bracer (w/Sphere Frog)
Stats: 6942/2552/1938/2120 (heavy buffing with stat imps)
BB: Fills BB gauge of allies, gives thunder element to all allies' attacks for 3 turns (level 10)
SBB: 14 combo thunder AOE, BB gauge refill & gives thunder element to all allies' attacks for 3 turns (level 4)

God Eater Lira (helper, B)
Level: 100/100
LS: 25% boost to ATK of all units, all allies' attacks has chance to inflict random status ailment
Sphere: Steeple Rose, Beast Armor (w/Sphere Frog)
Stats: 6710/2379/1879/1935 (heavy buffing with stat imps)
BB: 11 combo dark AOE (level 10)
SBB: Strong 13 combo dark STBB (level 1)

How the battle goes:

- Karl uses a water AOE every 5 turns (Frozen Axe), until 75% HP @ first form. Don't use items yet; you'll need it for his second form.
- Karl starts using these attacks @ 75% HP of his first form:
   > Verdant Axe (Earth), inflicts Weakness
   > Lightning Axe (Thunder), inflicts Paralysis
   > Flood Offensive (3 turn DEF debuff, ATK buff)
- 50% HP @ first form, he evolves into his 5* form, regains all HP, starts using Verdant Axe and Lightning Axe. Start using items now.
- 75% HP @ second form, can use a light STBB (Flashing Axe Combo)
- 50% HP @ second form, uses an extremely strong water AOE capable of one-shotting teams that are not mono thunder. Def buff from Elimo and Tesla's BB needed to survive without guarding. Even then, Reeze and Tesla died, Lira was in the red zone, everyone else very close to red, except for Lodin.
- After Blue Execution, Karl can use a strong water AOE at random (Cursed Blue Slash). Two or more in a row is not unheard of.
- 15% HP @ second form, uses an attack that gives him DEF buff and regens health (approx. 7000-7500 HP per turn) for 3 turns. Reapplies this buff 5 turns after the last turn he regens HP.

How I beat him:

- Elimo always heals and reapplies DEF buff as soon as she can use her BB. ALL Fujins go to her.
- Don't mind SBB! As soon as a unit can use their BB, I used it, except Elimo and Tesla. SBB takes too long to charge up.
- Tesla's BB is saved for Blue Execution/Frozen Axe.
- Lodin's BB is needed to deal more damage.
- Save all items for Karl's second form. YOU'LL NEED THEM.
- Activate Tesla's BB @ Blue Execution and make sure Elimo's DEF buff is still present, and you won't suffer a total wipeout, even without guarding.
- When he hits 15% HP, you're pretty much home free, so slug all you have at him.

So there! Hopefully this helps in finishing off Karl.

See you!