I've been on an Ornn kick these last few days, so I think I can pop in and give my thoughts:
--Forging weapons in-lane is useful, but what he can forge is very limited. If you prefer to build something not on his list of forgeable items, you have to tele back to base or build something else. Otherwise it actually has been a fun mechanic.
Ornn can forge anything non-consumable. Just open the store tab (click the button showing how much gold you have), search up an item, buy it, and he'll forge it right up.
--I do not like the end result of his Q. So far the other top laners I have faced easily sidestep this even if I cast it through enemies. The pillar it makes should either be bigger or deal some damage. Otherwise, I think the damage on his Q needs to be upped just a tiny bit more.
Damage doesn't need increasing, but I think the pillar needs to pop out a bit quicker. Not much, but the current delay time really prevents you using Q -> E as emergency or initiative CC, because when you throw the Q, even the most brainless player can/should be able to figure out what's gonna follow shortly thereafter and get out of the damn way, even with the meager slow that Q applies. That being said, if they make the pillar instant or even just half the delay it is now, it might make him too strong.
As a side note, I now play him as a Jungler, and he freaking thrives there. Doesn't even need pots. Hunter's Talisman + Rejuv Bead = endless jungling, and then you can just buy the Stalker's Blade and boots after your first round, which makes early ganks that much more intimidating, because you're literally going to be the first guy on the map who's bought anything.
His ult is probably one of the most satisfying things to hit. I wish it didn't scale off of AP though, because that just feels pointless, he never buys anything AP related, and it's only a .2 scaling. Were I Riot, I would remove the AP scaling due to the pointlessness of it (any serious damage that Forge God does is going to be done by hitting twice with it, thereby applying and popping the Brittle mark for the %MaxHP dmg) and instead do a low, low scaling via Armor instead, just so the player doesn't feel obligated to buy something AP to get use out of his scaling, and instead make the player feel good about making intelligent purchasing choices, because tanky stuff is always going to be good on this guy.
Final note: There are times where I charge into a wall expecting to knock someone up, only to come up like a hair's breadth short. Like, I'm standing literally at the wall at the end of my charge looking dumb. I would enjoy it if Riot gave Ornn's E ability a QoL passover, such that if you end your charge with the character model basically touching the wall, the knock up should trigger. In the same vein, E is sometimes hard to use as a getaway tool, because you'll hit the corners of walls (typically around mid) that, judging by the visuals, you should be able to have passed. It's a guessing game that I'm not exactly thrilled to play when shit is going down and I need to get in, or get out of a fight.
That said, I enjoy virtually everything about this guy, from the badass Nordic theme song to the forge-themed abilities. I would buy a LotR-esque or Forgotten Realms-style Dwarf skin in a heartbeat though.
