Not Updated For Current Season
This is how I use my favorite character, Sion! IMO he has the best set of abilities of all the fighter champs. He has an AoE attack to farm minions early with, he has an ability that increases his AD by 65 passively, an ultimate that can take pretty much any hero 1v1, and to top it off, they give him a stun ability!
Destroys champs 1v1
Can get FB often with Cryptic Gaze
Ultimate can give survivability in team battles
Easy to play aggressively early with his boosted AD and stun from abilities
Slow movement speed
No real escape mechanism
Health loss from Enrage early can be an issue, leading to easy harassment from range
Its difficult keeping enough mana around to use these abilities consistently, so you have to pick and choose when you use your stuns. You want to try and leave 100 mana open for his ultimate, especially once you get mallet. You can take alot of heroes 2v1 with his ultimate because of the lifesteal bonus it gives you. Your biggest problem, as with most fighter builds, is stuns. If its being a big problem you could always switch mercury treads out for berserker boots, however Attack Speed is the very heart of Sion, since his Attack Damage is boosted Innately.
Exhaust is a no brainer. Early game you can stun an enemy and beat up on them, then exhaust and keep wailing on them.
Ghost is important because Sion has no real escape mechanism, and my build doesnt really have much movement speed. It can be used to chase, escape, or get somewhere very quickly.
Teleport is very useful, but Ghost can work just fine getting around, and it gives you other benefits too. I dont use it, but to each his own.
Heal I like this because it allows me to play very aggressive in early lanes, helps keep the level curve in your teams favor. If sion gets his ultimate early, it can be game over early. Sucker an enemy in with your low health, stun him, and go to town with your partner.
This is my first build, so give me all the thumbs downs you want lol. I r nub, and im not easily offended!