Cloud dragon should also give +5%/+10%/+15% attack speed

Faster Recall/CDR on Summoner spells would be better imo. These both help ALL Champions. Lots of champions can't utilize Attack speed

Give the attack speed, but only out of combat.

It would have to give something helpful for every champion though. Champions that have little or no use for attack speed won't really receive much benefit from it compared to most.

Cloud drake should just give +15/25/35 movementspeed combat included