Riven (The broken blade)

Broken! Ha! Yah I would tend to agree with the broken blade part as she is most definitely broken. Shes been the go to champ for many a player playing top lane since. The meat and potatoes champ of top so to speak. Shes been nerfed and buff many occasions as Riot couldn't seem to find the right balance and to many still haven't. Anyway I would like you on the boards to look over this small change and give helpful feedback and thoughts if you think good idea or not.

(currently) Valor: RANGE: 325 COOLDOWN: 10 / 9 / 8 / 7 / 6 ACTIVE: Riven dashes towards the cursor and gains a shield that absorbs incoming damage for 1.5 seconds.

(proposed) Valor: RANGE: 325 COOLDOWN: 10 / 9 / 8 / 7 / 6 ACTIVE: Riven dashes towards the cursor and gains a shield that absorbs incoming damage for 1.5 seconds.' Should Riven not take any damage while Valor is active cooldown is increased for another 2.5 seconds.

Reasons for this... Feel there is no downside to spamming that e key in any situation. To engage(as it should be used) or to run away.
Valor means to have great courage in the face of danger, especially in battle and there is no valor in using e to run away. So with that said I think there should be an Achilles heel to this said move.

Thoughts greatly appreciated!