Hi, I'm new to making builds and recently made my own build that I think I should share with you. Please feel free to write comment about how this build can be better and comment your scores!

I get these runes because Sion would be really effective with more attack speed. He will lifesteal 50% more with his ulti and be doing a lot of damage.

I play with a 8/21/1 because my build doesn't provide a lot of the defense he needs. -DONT READ THIS- ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF ASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDFASDF -DONT READ THIS-

I think the items are pretty self explained but I'll explain them anyways.

Manamune: Great early game item, because it gives your AD and each time you use a skill or attack you gain more mana which makes you stronger.

Mercury's Tread: When you're running away this item sometimes can save you from stuns or slows.

Atma's Impaler: A really good item for Sion because:
1. Gives armor.
2. Gives critical strike.
3. Give damage depending on your HP. which you'll have plenty of.

Frozen Mallet: Gives HP and is a good chasing item.

Madred's Bloodrazor: Since you destroy the squishys already.. why not destroy the tanks now.

Phantom Dancer: More attack speed and crit and movement speed!

Feel No Pain- Sion has a 40% chance to ignore up to 30/40/50 damage each time he is attacked. The damage reduction is calculated before armor benefits are taken into account.
Cryptic Gaze- Blasts a single enemy, dealing 70 / 125 / 180 / 240 / 300 (+100% of ability power) magic damage and stunning for 2 seconds.
Cooldown 12 / 11 / 10 / 9 / 8 seconds | Cost 100 mana | Range 550
Death's Caress- Sion surrounds himself with a shield which absorbs 120 / 170 / 220 / 270 / 320 (+100% of ability power) damage. If the shield is not destroyed in 10 seconds, it will explode, dealing 120 / 170 / 220 / 270 / 320 (+100% of ability power) magic damage to surrounding enemies.
Cooldown 4 seconds | Cost 70 / 80 / 90 / 100 / 110 mana | Range 1
Enrage- Toggle: Increase Sion's damage by 25 / 35 / 45 / 55 / 65, and he gains 1 / 1.5 / 2 / 2.5 / 3 maximum health per kill.
Cost 6 / 8 / 10 / 12 / 14 health | Range 1
Cannibalism- Grants Sion 50 / 75 / 100% lifesteal and 50% attack speed for 20 seconds, additionally Sion's attacks heal surrounding allies for 25 / 37.5 / 50% of damage dealt.
Cooldown 90 seconds | Cost 100 mana | Range 1

Ghost: Your champion ignores unit collision and moves 32% faster for 14 seconds.
This is good for chasing and running! So always have it up before teamfights.
Exhaust: Blinds the target (100% miss chance) and slows its movement speed by 40% for 3 seconds.
This is a good spell to slow them down if there a few steps ahead or a quick melee one on one!

Doesn't look so good? Please try it out and comment! Feel free to rate!