Pantheon is normally a champion to make tons of damage and being a strong tank the same time...That's why I follow the build that i made to help you!

The runes are the typical runes that a tanky DPS fighter uses...9 Greater Seals of Resilience for the needed "Armor" , 9 Greater Marks of Desolation for "Armor Penetration" , 9 Greater Glyphs of Warding for "Magic Resist" and finally 3 Greater Quintessences of Strength for "True Damage/Physical Attack" .

The mastery page is also the typical of a tanky DPS so I think it doesn't worth to be mentioned!

For the solo top I buy for first item the "Boots of Speed" to avoid the enemy basic attacks and casts and 3 "Health Potions" to use in case you lose some of your HP.Then my next item is "Warmogs Armor" which gives Health and Health Regen, needed for the HP tank!Afterwards I complete my boots buying the "Mercury Boots" for some more Magic Resist.Then the phage is an also needed item for this build because it gives Health, Physical Attack and Slow for the ganks or generally the chase of someone!I complete it with the "Frozen Mallet". After that I buy the "Atma's Imparel" to get some extra Physical Attack from the HP, Armor and Critical Strike. Moreover "The Bloodthrister" is also needed for more Attack Damage and Lifesteal. My last item is "The Guardian Angel" because it gives Armor and Magic Resist but the main reason I get it is that if you get slain, you can resurrect in the fight and keep dominating!

For the skills Level Up I follow the raw of:
-Spear Shot at levels: 1,3,5,7,8
-Aegis Of Zeonia at levels: 2,14,15,17,18
-Heartseeker Strike at levels: 4,9,10,12,13
-Grand Skyfall at levels: 6,11,16

The "Flash" is needed for surviving if you are getting chased, or if you chase somebody else. Also "Ignite" is needed to kill somebody on low HP or stop the Health Regeneration of him.

+The pros of solo top Pantheon , are that he is strong enough to counter many of the solo top champions.
+He got stun which is useful, as cc in team fights.
+Also he has a very good way to escape or join a fight even being far away from it, his ultimate the "Grand Skyfall".

-The only drawback that I think he has, is the lack of mana at the early game

The way of farming that I suggest if last hitting so the jungler have the opportunities to gank!

If you want to play aggressive you may push only if you have ward near the baron and flash.

If you just play last hit then the jungler will gank easily.

In case you push your lane the jungler may come for a ninja gank from your bush but you need to push a lot until the jungler goes into the bush, and then wait for the enemy to push.Then you engage first by stunning the enemy and you secure a free kill!

I hope my build will help many people to dominate the solo top lane on 5v5 games!
If there is any mistake in my build please say it so I can correct it.
Good luck and have fun summoners!!!