This as you can probably tell is a build to utilize Ornn's strength in the jungle. In my opinion, if you can utilize Ornn's kit properly, he can be a very effective jungler with fast clear times and powerful ganks. With that being said, I make this guide to sort of focus his power into jungling more precisely.

I think the rune choice is quite obvious as resolve as a main given that ornn is naturally very tanky and this helps that. Then with domination as a secondary because pretty much almost all junglers use domination in their primary or secondary.

This is where the build starts to get fun. With ornn, you have a lot of options but i think the best choice to be for the standard build to involve ninja tabi, kind of a given for a tank, a bloodrazor as the jungle item for the mana regeneration because ornn is a mana heavy champion. Then, i chose the black cleaver just because it is such a versatile item, same with the sunfire cape. And then the Trinity Force because Ornn needs to simply do more damage as something like another health item would not be enough. And finally, the titanic hydra as the final item because it is again a very strong but versatile item. With respect to the Final Build against heavy AD, this uses almost all armor and health items to account for extra damage being dealt. And of course, the build against AP involves the same concept but magic resist.

Later in the coming weeks, you should see videos uploaded of my gameplay with this build, and that is all for this build.