Selena

This build attempts to make use of Selena’s high speed and her natural bulk while patching up her low attack stat. Selena works as a more defensive version of standard Wo Dao builds while still being able to ORKO a large portion of the roster.
Wo Dao+ plus Atk effectively leverages Selena’s poor attack into something a little more passable and allows her to effectively use low cooldown specials to deal burst damage.
Moonbow is the most efficient special to use in conjunction with Selena’s high speed and the Wo Dao+. Bonfire can be used to make use of her bulky defense stat, but it is often overkill and the longer charge time makes it less efficient.
Reposition works well as her support skill and allows Selena to effectively save allies from being attacked or even bait enemies to attack her instead.
Fury 3 is the preferred A slot skill as it boosts her speed and attack while maintaining her bulk. Life or Death 3 is also a viable option for maximizing her offensive output, but this hampers her enemy phase effectiveness.
Sword breaker 3 is an excellent choice for Selena’s B slot as a counter to many top tier sword units like Ayra and Mia who comfortably avoid doubles even at 41 speed. Desperation is another excellent choice for securing consecutive attacks on slower heroes and sweeping with low health.
Selena’s native Threaten Speed is an excellent choice to secure double attacks on speedy heroes after successfully tanking the initial hit. Otherwise, any skill can be effectively used in the C slot depending on the role Selena is filling.
The S slot is filled by the plus 3 attack seal to patch up Selena’s low attack to a reasonable level alongside Wo Dao+ Atk version from the weapon refinery.

This build is the sustain tanking Selena build of the century. The build truly shines when you truly commit and Summoner support and +10 this gal.
+10 and Summoner support bumps these stats up to 48/45/41/45/34 then combined with Close Def and Steady Breath Selena gets 55 Def when attacked by melee. Swapping out to Ignis brings the damage potential to crazy levels if you just need to her tank and destroy 1 unit.

The man, the myth the legend, the Selena god himself with the freshest Selena build to grace the Earth. 55 Defense when attacked by melee units, hit back for +20 damage Aethers and heal off the minor damage you took, debuff the mages or other units they have. This build does me well in Tier 20. Just bring something to deal with Blue tomes and Red tomes and she can tank everything else, +10 Effie? No problem.

Selena was the first unit I ever summoned, and is probably one of my favorite child units from Awakening, so I felt obligated to make her into something worthwhile.
TA was picked to basically deal with all the green units. Tbh I never expected her to beat a Brave Ike until I witnessed it happen. I kept armor slayer to help her handle any Hectors, but it can be swapped out for any sword really as along as it's not the Ruby Sword.
Swordbreaker is probably her best B skill. She's outclassed by most sword units, so this'll help a bit on the battlefield.
Threaten Speed was picked to ensure she doubles, and the +Speed sacred seal can also help with that.
+Attack Selena is preferred, but even with my speed boon and attack bane, she still works out pretty well.

[+Atk/-Res] +6

**Notes below apply to base Selena without merges, while her stats above reflect merges

This boon/bane set is the only viable IV aside from +Atk/-HP to make Selena worth such the expense (and -HP will harm her tanking abilities with Fury equipped). She is primarily a melee tank with good res who relies on her special to make most kills, but is a jack-of-all-trades unit. Note: this spread involves +4/-4 in those stats.

Fury is the best choice for A Slot because none of her stats want to be ignored. It boosts her poor attack, brings her speed to a respectable 38, bolsters her defense to a powerful 35, and repairs her resistance at 27.

Renewal was chosen to help counter the effects of Fury and increase Selena's survival. Vantage could be an alternative option.

Threaten Spd allows her to gain doubles she may have missed before, as more doubles means a faster special. The combination of Wo Dao+ and Bonfire gives Selena an additional 27 damage, making her deadly.

Deflect Magic will help her survive her biggest threat: blue mages. The idea is to barely pull through and then destroy her attacker on the next turn. Otherwise the HP seal is a good alternative.