Hello everyone. My name is fizzacle and this is my Toplane build for Aurelion Sol. First of all, this is my first build/guide, so expect some mistakes here and there. I only got to test this build once, so I would not recommend using this build in Ranked games, as it might lose you the match. This guide will hopefully be updated regularly to make it look good and provide as much information as possible if anyone plans on testing this build out for themselves. Comments would be appreciated.
My English is not perfect, just a note. :)

PROS
- 200+ Armor!
- CDR allows Starsurge and Voice of Light to be used more often than usual
- Survivability against heavy AD champions
- No need for MR if enemy team is full AD, allowing you to get more armor or damage

CONS
- Weak against AP if no MR is built
- Reliance on teammates for heavy damage
- Not a lot of MPenetration
- Lacks Health

[Q]Starsurge:

This is the skill you want to max out first, as it is your only source of hard CC. It also can be spammed (kind of) when you have full CDR. In Teamfights, try to catch as many enemies as possible with your Q, because your goal should be to provide CC to your team.
A possible way to use your Q would be to use it to escape, as it grants you some Movement Speed.

[W]Celestial Expansion:

You should max the W second, as it deals damage. Besides, your E will have a shorter CD thanks to the reduction and travelling some units more in comparison to increased damage from your W is not worth it.

[E]Comet of Legend:

This is the ability you want to max last in most situations. If you struggle in lane and want to roam & gank other lanes more than usual for your teammates to get a few kills, you could try maxing this one second.

[R]Voice of Light:

Give it a point when you can. This is the ability that might save your team if the enemies get too close to your team, as it will knock them back to your activated W range, so keep that in mind. The same applies to you if you are in a dangerous situation.

Quintessence: Flat Ability Power for more damage.

Mark: Flat MPen for more damage against people who are stacking MR.

Seal: Scaling Health for some health that this build (kind of) does not offer.

Glyph: Scaling MR for the lack of MR.

There are two possibilities regarding Aurelion Sol's masteries.

The first possibility would be to take the Resolve Tree with the Cunning Tree.

The second one would be to switch over from the Resolve Tree to the Ferocity Tree if you plan on playing aggressive. The only thing you have to decide is if you want to be more supportive and run Expose Weakness or go with Feast for some mediocre lane sustain.