How about instead of movement speed, cloud drake unlocks the old boot enhancements?

Title^

And the different level of cloud drakes unlock the different enhancements EG. 1 cloud drake: unlocks alacraty and captain enhancements 2 cloud drakes: unlocks distortion 3 cloud drakes: unlocks furor

(in case you didn't know what they did: http://leagueoflegends.wikia.com/wiki/Enchantment)

I just put them in the order i thought was best but can be switched. Elder drake will probably be a buff to whatever enhancements you have. Also if you have 3 cloud drakes you can still use the previous enhancements but you have more options basically.

We could also possibly have more enchantments to add to the list for more variety.

I feel like this would put more importance on cloud drake as instead of the 'meh' feel it has atm, you are more like 'gotta stop this 3rd cloud drake going to them to prevent their adc having even more kiting power (from the furor unlock)'