Senya needs some kind of buff to her 
- 2021.07.17 12:35 (UTC+0)
"Complains & Comparison"
Honestly for the "First Dragon Slayer", she's very weak. Lets take her survivability first since she's a Knight and not meant to be a damage(EDIT : Her kit looks more to taunting and buffing the team instead of dishing lots of damage, i mean sure she get 30% attack but she cant crit so that's not really worth turning her to a damage), she's still quite squishy and doesnt provide much for the team, lets take an example like FCC, she deals a bit of damage too BUT she can gives the team barrier and skill nulify which is great for the team to survive, then A.Ras he's free and he's also much better than her, A.Ras can Decrease Defense, Increase Defense for the entire team and also Dual Attack. There's still a much more better choice for tanks rather than senya because she doesnt deal that much damage, and her buffs are too RNG also its just one turn.
Now let's compare the damage with other knights Senya cant crit and the 30% extra attack isnt that great to negate the chance to not crit, look at Charles he can easily one shot people if he wanted to, and for a damage knight he even strip buffs from the enemy. Another unit to compare is G Purgis, he's build for health, and can increase the team combat readiness, deals quite the damage around 4k-5k if it crits, he also has the ability to stun people. There a lot more Knights that can dish tons of damage rather than Senya.
Her Artifacts do help her damage but it's not enough to make her deals enough damage since she cant crit and her attack doesnt even pierce the enemy defense. Chipping through health wont do anything at the current meta on E7, making the Artifact penetrate the enemy defense would also be great or turn it into some kind of Kluri heal per turn.
Honestly buffing her is quite hard i think some simple solution i've had in mind is:
Since she's made for not to crit, put some defense penetration for her S1/S2
Her S1 and S3 scales with HP/Defense
(For Tankiness and Survivability)
Make her S2 for 2 turns with 3/4 Cooldown
S2 increase Health & Defense by 5% or 10%, or if her health is getting lower her defense will increase
Let her S3 reduce combat readiness of the enemy
"I've keep saying on defense penetration is "purely" on my own ego and not Logically thinking, its because she uses quite a big Lance (Not a Spear) and she can kill dragons(they usually have tough scales)"
Honestly those are some of my thoughts, i like her design and i use her quite a time just in term of "Waifu" and not "Competitive.
Any type of buffs is welcome and i think it will make the community happier since she got good Art Style and quite an interesting mechanism, there are tons and tons of better Knight for now to tank, damage, or utility. She felt like a 4 star(even 3 maybe to put in with Gunther) instead of a 5 star
Hell even Soul Weavers can do a better job at tanking than her.