|This build is meant to utilize Corrin's good speed and def in order to turn her into a flexible physical tank that is capable of trading with almost any non-red unit.
Her optimal boon is +Spd due to it being a super boon, giving her +4 spd rather than the normal +3. However, other boons such as +Atk are also acceptable alternatives. Because this build is focused on being a hybrid sponge, -HP is her optimal bane, though -Res is also acceptable.
Lightning Breath+ is her optimal weapon choice, allowing her to counter attack vs bows and red magic, which she can usually deal with. In addition, the detriment of the +1 Special Charge is not as detrimental due to the rest of her kit. +Def is the best refine in order to increase her most important bulk as much as possible.
Reposition is a powerful assist for enemy phase tanky units, but other options such as dual rallies are also very strong.
Ignis is essential for letting Corrin deal damage, as it will activate every other combat and helps pad her mediocre attack stat. If using Steady Breath, Bonfire is preferred because it activates every turn.
Sturdy Stance 2 is a great budget skill to use for EP, as it gives Corrin a good stat boost without any further condition, whil Steady Breath offers a very powerful boost in special charging, but is much harder to obtain.
Quick Riposte 3 allows Corrin to always ensure she doubles the enemy. While her speed is solid, it generally isn't high enough to let her naturally double her enemies, but in a place where she usually doesn't get doubled.
Fortify Dragons is Corrin's natural C skill and is very good, but can be changed to suite the requirements of her team. Other common C skills are other hones/spurs, Panic Ploy 3, or smokes.
Depending on what threats you need Corrin stand up to, her S slot can change between Distant Def 3, making her more durable against ranged threats, or Close Def 3 which makes her more durable against melee threats.