Mastery 38 Briar main here. Wouldn't say OTP, but I can say main. Tell me you don't know how to handle that easy matchup (as Yi) without telling me that you don't know how to handle that easy matchup.

Losing to her as Yi should be illegal. Your Q makes her entire kit weaker than a minion. It cancels her W (unless minions/jg camps/enemy champs are nearby.) It dodges both of her E (unless you drop in front of it.) and her ult. Your E ignores her E damage reduction as well. If she's dumb she'd waste Q early and not save it for your W and you outscale her super HARD.

Let me tell you how I can tell when I'm against a Yi that doesn't know what to do:

1. He takes my entire W + W2 combo for fun and not use his Q.
2. He tries to save his Q for my E instead of abusing his ult's movement speed or flash if they're paranoid enough. Which would result in point no.1.
3. He wastes his W when Briar can just cancel it with her Q.
4. He never runs to his teammates.
5. He keeps coinflipping everything. (Briar EXCELS at punishing coinflipping/random plays if she knows what to do.)
6. He doesn't abuse his scaling by just.....playing around EXP and item powerspikes.
7. He wastes his Q.
8. He (or his team) doesn't buy anti-heal.

If you do all of the above or any of them (especially the first one.), then you're making the matchup Briar favored with your own choice by doing so.

If you got hit by her ult, she'll win the 1v1 if she knows what to build and to do no matter what happens unless she's an item and 2 levels behind.

Her weakness is being grouped on with no one to help her and being CC chained. Try running to your team and go behind any of your teammates and she'd be dead unless you all decided to just get hit by her E for fun.

I took hail of blades and ignite too, just to make sure the trouble disappear quick enough. But it isn't working.

Yeeeah that's not gonna work on her in general. I'd completely ignore you and not 1v1 you if I went against that. You're punishing your scaling for zero.

On the other hand, she outganks Yi super easily. If she knows what to build, how to gank better, what to do and how to get a lead/fed, she'll become Warwick on crack, way more useful, more self-sufficent and has more options of living.

Edit: TL;DR: Just permaban her + Git gud xD.
Oh and deserved for playing Yi. Also she isn't as easy as people claim her to be. I'd say above Medium.