[@Rune_Alchemist]

I understand your point, don't worry. You're by no way being hostile.

But the point is: its impossible to know that she took quite a lot of damage. In your post, the sensation it passed was literally that she shrugged off that attack without any complication. There is no additional info saying "oh, I took some damage" or something like that.

The target finding spell is not 'homing bullets' (she actually has a spell for that, but only purely magical projectiles), but simply something that helps her find the optimal trajectory & etc.

About the one-shotting thing: I never wanted that. But just be mindful of one thing. If someone gets close to Yasha and hits her with a sword, she will be gravely wounded. There is no 'mumbo jumbo' to save her. With enough power, a melee character able to keep up with her fly spell could literally slowly cut of her arms, legs until there is nothing remaining. She is just a human regarding her defenses.

I understand the tactic about not showing her wounds, but... in your post...

"All Yasha was doing was just pissing her off more."

"a much more powerful explosion than she had expected - but nothing she couldn't handle. If Yasha was expected screams, no, all she'd hear was laughter as the explosion leveled the entire area. Senna seemed to almost ignore it entirely as even the blast from the explosion didn't seem to stun, knock her off her feet, or even hinder her speed. She could feel the blast of magic burning her back - her tail might have gotten a little singed, almost."

You see? You don't mention the fact that she actually took damage or anything. She literally shrugged off a glass cannon's most powerful spell without even falling down, without even feeling anything at all.

In your CS, the weakness section says: "The most obvious weakness of Senna's is the incredible lack of defense. Oh, certainly thanks to her class she has a massive pool of health compared to most other classes, but with armor reduction equivalent to light armor she takes the full brunt of any sort of damage dealt."

But... she literally took a magical nuke to the face without even flinching...

i'm not trying to be aggressive or anything, but I really don't feel like Yasha can do ANYTHING against Senna... Yasha just used her strongest spell. As I said previously, I designed this spell to take an entire post just to cast, only firing it on the other one.
Yasha has very obvious and blatant weaknesses, she cannot hide herself after she shoots, needing to reposition herself. She is basically a human regarding her defenses. I repeat, if Senna got near yasha and hit her by surprise, she would DIE. Yes. Die. No magical shield... If she took a swing to cut Yasha's arm, that is exactly what would happen.

And I didn't even mention Selena... Selena did nothing at all against Senna. Her attacks, her curses... everything was absolutely useless...

I ask once more: What would Yasha be able to do? She just fired her strongest spell, and NOTHING happened. I can't simply fire it twice because it would be overpowered and ridiculous, since it is supposed to be a spell with a long casting time. Other bullets, no matter what I do, simply don't affect Senna.

Her 
[hider=Sanguine Amulet:]
The blood red gem that hangs around her neck glows slightly. Simple in name, and in effect. It offers protection to the user against other blood magic, and to a lesser extent other magic. A fearful blood mage that feared that his pupils might turn on him is said to have created it. It forms an ethereal, near invisible shield around the wearer that weakens all incoming magic attacks.
[/hider]

pretty much negated Yasha's shots. And they're not puny shots... Yasha is made to be a glass cannon. And I mean a REAL glass cannon. Touch her, and she will shatter into a million pieces

The way I see, Senna is both an unkillable tank and a fast and agile assassin.

I mean, I didn't mean to literally one shot Senna. Since she has her amulet, I thought that it would be enough to save her from death, but not without temporarily incapacitating her.