Balanced idea's to make Sion more viable

As you all know Sion's update made him look very impressive but his kit is a major disappointment. You often will miss your ultimate and even if you do it does penny's worth of damage and second of all when Sion dies its very easy to get away from him if you have any cc or dash I really feel this takes away from the unstoppable juggernaut feel riot tried to give him.

Now here my ideas to lessen these disadvantages without making him over powered. 1st. of all Sion cannot go below 1 hp while using his ultimate, this further add's on to the unstoppable aspect of him but this doesn't mean you should always ult in no matter what hp you have because you will die pretty much immediately after the ult ends. :)

2nd. of all when you use soul furnace during your ult it will increase the size of the red energy (aka hit box) of the ultimate making it harder to navigate but allowing you to hit more enemy's in exchange.

My 3rd. idea is to allow players to charge up decimating smash while ulting (at the cost of speed until 1.75 seconds when he gets the AD increase) to increase the damage. To balance this decimating smash will charge at the same rate unstoppable onslaught does hence the longer you charge hence encouraging players to ult farther away so it does more damage. I personally thought seeing Sion with his Battleaxe raised to his side bashing it into the enemy team would be quite frightening. The major downside of this would be that you cannot use your q directly afterwards to get a second stun off.

Next on to glory in death my three ideas for this are recommended separately because if they were all added in his passive would be OP. 1.)Sion's passive works like Soraka's passive but instead he charges faster towards enemy's faster and it is 2 seconds long. 2.)Sion's death surge is extended by 0.5 seconds every time you hit an enemy. 3.)Sion is immune to cc when he uses death surge and death surge is 2 seconds long.

(Audio idea's) My question is why is there a metal groaning noise when he ult's that everyone hear's? I don't have anything against the noise but I would think having Sion's scream heard by everyone a lot scarier. Lastly something I am less sure of but I think should be thought about is should everyone in-game hear Sion stomping get louder or quieter depending on how close he is to you. The stomping could just be heard globally (or not at all) but I think having the stomping as a mechanic would help the enemy team know where he is going (because stealth isn't Sion's element) would add to the fear of his ult and on the down side give the enemy's time to get ready.

These are the idea's for Sion that I think would really give him some more life and give some fun new mechanics and choices for ulting, I hope you agree. Please let me know what you think if its OP or there is something else that could be added. This is the largest thing for a game that I have written in a while.