Fiora's W blocking on-hit spell effects

Not to say directly that Fiora needs any buffing, but I feel like her W is a little bit pointless. You block one autoattack and that's it. Some might argue that a single auto-attack could mean the difference between life and death, and that's fair, but how often did that honestly happen and how often did you feel actually rewarded for mashing the W button as soon as it came off cooldown?

I think it would be cool if Fiora could block a whole auto-attack with effects and all implied. By that I mean auto-attacks like Udyr's E (stun included), Diana's passive's third strike (The magic damage too). Mainly things that add either an effect or bonus damage to their auto-attack, instead of just the physical damage part of the attack.

It would separate the good Fioras from the great Fioras (sorry.) by allowing them to gain an advantage from properly timing their W.

And, as a small plus, it could also send back a percentage of the damage to the one who gave the attack. Something like 10/30/50/70/90% of the damage inflicted gets sent back.

Too much? I just want to discuss this because I feel like it would be a fitting change to her without possibly overshooting her any more.

(Please try to keep the discussion intelligent and meaningful without being rude about it. I'm just pointing out something I noticed/thought of. I don't know how gamebreaking such an idea could potentionally be.)