Berkut

"Ugh, I should not play games while drunk anymore."
A build created by drunk me a good while ago, making me question my thought process during the procedure.
Enough of me being drunk though, let´s talk about the build.

Pros:

This build works suprisingly well, spreading a lot of debuffs after combat and surviving multiple encounters thanks to Fortress Def, Distant Def and his lance, giving him 36DEF (42 when ranged) and 34RES unbuffed (except against dragons).
ATK Smoke allows him to survive even better, after tanking a hit from an enemy.

Oh and him being on a horse is pretty neat....
...that is, if you´re willing to give him a slot in your Horse Emblem team.
_

Cons:

Fortress Def reduces Berkut´s attack, making him hit like a wet noodle, if his Bonfire is not up.
His role is strictly tanking and debuffing, making him much less flexible in pretty much anything.
_

But that´s pretty much all I can say about the build.

This build works to maximize Berkut's natural bulk and put him to work as a healer. Berkut's Lance+ provides him with decent offence in addition +4 Res when attacked. Distant Defense adds +6 to Defense and Resistance when attacked at range and Sacred Cowl further reduced ranged damage. Renewal grants Berkut some extra staying power as well as a way to continuously act as a healer. Reciprocal Aid will often allow Berkut to heal his allies to full with his pretty good HP and his bulk makes it unlikely enemies will be able to score a kill on him after he heals an ally. You could also run Ardent Sacrifice on Berkut if you'd rather not leave him on low HP and are fine with healing smaller amounts of damage but from my experience Reciprocal Aid works out fine for him. As for his C skill obviously you'll want some kind of Horse buff but specifically which one you give him will depend on your team composition. However if you're not running him in Horse Emblem then Threaten Attack or Speed could help him tank even better while offering the same benefits to your allies. The Resistance+ Seal just gives him extra protection against magic, but this could really just be replaced with whatever works best for you. And finally the S summoner support is very beneficial giving him more HP, Def and Res for tanking/healing and some better offensive potential with added Attack.

This build aims to capitalize on Berkut's niche of higher resistance than other cavaliers, while giving him more specialization due to his speed, which would otherwise cripple him via double attacks.

By giving Berkut a Sapphire Lance, he turns into a horse that can effectively tank and deal with some of the most common threats of arena in sword units, while also being able to take on powerful red mages such as horse emblem Leo, Celica and Tharja simply due to Sapphire Lance's TA effect and distant counter, taking advantage of his surprising balanced bulk.

To this end, quick riposte is used to secure kills, though blue tomebreaker can be taken to help Berkut defeat blue mages such as Linde and Olwen, allowing him to duel them by tanking one attack with his niche res.

Bonfire is given due to it being his best 3 cd damaging skill, especially given that he will often be going against swords and mages, neither of which have a majority that are bulky enough to necessitate Luna instead. Berkut can take next to any seal, though HP +5 will generally help to boost his overall bulk.

This build on Berkut gives you the maximum potential to his Res based build.
Berkuts lance- gives him Res+4 if attacked giving him 29 with the seal.
Water boost gives him an effective 35 Res if he has 3 hp higher
Cancel Affinity is used to check Julia and Cecilia who do effectively no damage if he reaches this resistance... he can also get Buffs from Horse emblem and have a 41 Res stat which is phenomenal. They won't do ANY damage at that rate
Savage blow is optional... it's only used to add damage to non mages like Ryoma to ensure an OHKO so vantage doesn't activate.

Iceberg can deal up to 26 damage up and 3 cooldown isn't that much, He can commonly do 17/20 bonus damage

This build can be a great check for those pesky Cecilia's or Julia packing TA.

Berkut's Lance is a bad weapon, but is budget and offers some protection from mages. This build focuses on fighting off red and blue Lance units. Defiant Def helps tank physical Attacks, while Lance Breaker is to counter other Lance units. Bonfire helps capitalize on his decent 31 defense, 38 with Defiant Defense 3. Swap helps reposition him and Spur Speed helps support other units to double.