Clever Way to nerf Fiora

Ok, so right now Fiora's ult is being used in team fights not to shred town target opponent, but instead being cast on the most likely to die in the next 2 seconds target, then using the free massive heal for a teamfight win. That is far from intended, and needs to be fixed.

My idea is that Fiora's Ult AoE heal strength be based on how many of the targets she hit. If none are hit, then it's basically nothing, but it all 4 get hit, then it works as usual. That way she isn't a super strong AoE healer in team fights, instead a single target destroyer that can get an AoE heal if she's done her job well.

Another idea is to make Parry not 100% invulnerability to absolutely everything. Maybe have her actually eat debuffs like Death Mark, or not let her block summoner spells.

While on the subject of nerfs, let's look at vayne. Some Ideas I had were:

Actually having a real mana cost on her tumble, so she can't spam infinitely, along with maybe a higher CD early.

Higher Ult CD

Here's a good one to work off of the other two. If you give her Q a higher mana cost, when vayne ults, she could get cost reduction on Qs (back to original value) for the duration of the ult. That gives a real window of power thing for her. Heck, maybe even make her Qs normally have a longer CD, but lower that for the ult. That could be a good trade-off for taking away AD from it.

Remove base damage on SBs, so she doesn't squishy shred as hard

Reduce the knockback on Condemn so she doesn't self peel as hard, and has a harder time connecting with walls.

Higher Ult CD

Reduce the free AD vayne gets from her ult. Right now, she can build loads of AS first, and still have her normals AAs hit like a truck because she has the strongest AD steroid this side of Mundo or Darius

What do you guys think? We all know these champs need to be knocked down, so let's give Riot as many ideas as possible.