Sion E should have a longer cast time
I've noticed when playing against sion that if you happen to be a lane bully, you cant really do much to him. My experience is that he stands behind minions and just E's you (an ability with no cast time, that goes through minions, slows for a LARGE amount and removes armor, does a fair amount of damage especially if he has comet, has a range longer than Jayce Q as well as moving faster). This gives very little room to react unless you are gangplank or some farm champ early in which you just try to stay as far back as possible. This begs the question: why doesn't it have a cast time? It requires a friendly minion to launch, which means it can work in almost a 145 degree angle, this can put someone way out of position to even give them a chance to dodge it. It seems a little more reasonable if it has a longer cast time, even if by a little.