Frederick

The saying goes that "The best defense is a good offense" and with Frederick, it couldn't be truer. With his large physical bulk, armored units aren't the only ones that get destroyed.

He is able to take a lot of damage due to his DEF boon and his weapon +Def, and Deflect Magic 3 allows him to not be decimated by magic attacks. He can usually take the first attack like a champ with his high HP, and with his low speed almost guaranteeing him to be doubled on, the second attack almost does nothing thanks to Deflect Magic 3. Grani's Shield is the finishing touch to his all-around impenetrable defenses with Vantage 3 being his last resort, usually resulting in the other unit's death.

For his offense, with him being able to take so many attacks and with his attack state being so high, he is equipped with Ignis which, when activated is an almost guaranteed K.O. to any unit he is facing.

He is an irreplaceable unit in my Hone/Fortify Cavalry Team with those buffs making him something to be feared. He was one of the first units I got when I started this game and is by far one of my greatest. If someone has a Cavalry Team and loves Fredrick, I hope this shows that he's not just a good unit but one of the best.

This build utilizes Fredrick’s immensely high Atk and overlooked high Def to create a good enemy phase that can ORKO most lance, axe, and sword units in the game.

Brazen Atk/Def is a great A skill for Fredrick. His high HP gives it a high trigger rate so he can blow through most defenses while taking little to no damage in return. It can also allow him to effectively OHKO most blue and green mages, as well as some red mages.

Quick Reposte, in combination with Ignis, is absolutely devastating. Fredrick’s Spd is rather low, which means most units will double him. This means that Ignis will trigger, which is basically a guaranteed kill considering it boosts damage dealt by around 40.

Hone cavalry is a good C skill for cavalry teams but can be replaced based on team composition as well as his assist skill.

Close defense as the S skill is the cherry on top. It makes him nearly invulnerable to blue, green, and most reds. It even slaps on a little Res.

If nothing else, this build should at least prove Fredrick is better than the other units in his tier.

This Build Takes Advantage of Frederick's Defense and with Both Fortress Def Skills and a Defense Refined Slaying Axe Boosts his Defense To 53 Add Fortify Cavalry buffs and He Gets 59 Defense
And Bonfire To Take Advantage of Said Defense And Turn it Into an Offensive Strike As Well as Guard to prevent Specials Like Moonbow Luna or Aether From Cracking into The Wall.
Frederick's Only Weakness with this build is his Low Resistance meaning Any Mage Regardless of Color Advantage could Easily Obliterate Him His Attack Drops to 43 Meaning It will be Hard for Him to OHKO Enemies Entirely
As Well as Low Speed

This will help Frederick mostly during the enemy phase, utilizing his great defenses. Having Distant Def and Handbell+ (+Res) will really help dealing with hyper offensive mages, and maybe even some red mages, due to Quick Riposte ensuring a double.

This Frederick is built to kill.
The Slaying Axe+ allows a one-charge Glimmer.
Reposition is helpful for Unit Movement.
Glimmer allows a 30% raise in attack, and is almost allows active.
Death Blow helps to raise his attack even higher when he initiates.
Wings Of Mercy allows Frederick to move to any ally that is low to give them a helping hand.
Savage Blow allows a little bit of extra damage after combat which can help quite a bit.
And the Attack +3 is self-explanatory, allows for +3 base Atk.
(Note that these are the stats of with +3 merges)