Ornn is all about itemization and rune optimization. Your game starts at the lock-in screen.

If you want to become an Ornn God you must understand 3 things.

1- You must understand what your role is on the team.
The easiest way to play Vanguard role is to pocket your carries. (always stay grouped) As a vanguard, you have two main objectives.
- Get as tanky as possible to peel for the team.
- And to lockdown (CC) the enemy carries.

2- Wave Control
(this is basic top lane macro)
You will easily get abused in the lane as Ornn so the safest way to play is under the tower and to always let them push. You can do this by last hitting the enemy minions. Letting there be more enemy caster minions than yours will allow them to push the wave in your favor.

3- Itemization and Rune Optimization.
Always be conscious of the map. If you notice your botlane starting to feed you may want to get an early Randuins Omen (second item). If you notice your midlaner is feeding you may want to start building toward Abyssal Mask.

Early Game. 00:00min - 15:00min
You must understand that you are a late-game champion your early game is not very good so play safe. You have to remember that if you are losing lane it's better to give up the tower then to die and give up the tower anyways.
During the laning phase, You must have a good understanding of the roster of champions and their abilities. Meaning you must know the timings of their stuns and use your W appropriately that ways you come out on top when trading.

Mid Game. 15:00min - 30:00min
You hit a mega power spike at level 13 any 2 Masterwork items you get are created for free at level 13. every level after 13 ie. (14,15,16,17,18) you can upgrade 1 item per ally free of charge (which item is based on its priority in the slots inventory ie. Luden's and Rabadons it will upgrade whatever item is in the 1st slot and then goes through descending order).

During this time you should be looking to group with your team at objectives.

Late Game. 30:00 - ??:??
During this time is mainly Teamfighting so make sure you had built appropriately and lockdown the enemy carries. Do not chase for kills it's better to go for objectives like Baron, Elder Drag, or Inhibitors than it is to waste 10-30 seconds chasing a kill.