Thresh Ability (LoL): The Box
The Box Thresh
R
Range: 450
Cooldown: 120
/ 100
/ 80
Cost: 100
Once a champion collides with a wall, the wall is destroyed.
Any other walls struck by any other enemy champion slow for half the duration.
I can see Thresh going full AP just for that scaling. With 300 AP (which is way below the maximum) the first wall will do 850 damage (assuming The Box has been maxed and we are bursting one champion(Mobafire currently shows The Box doing 450 damage at rank 3 but I've cross referenced other websites and found it is actually 550 damage) and each other will do 425 damage. In teamfights Thresh can flash in, pop his ult and Zhonya's Hourglass while another ideal AOE partner ( Miss Fortune) bursts down the slowed enemies.
I can see this ult getting nerfed soon
Building full AP weakens his kit as a whole. He'd only do any meaningful damage with The Box. He's better doing an AD/AS build if wants to do damage because all of his abilities have reasonable to very good base damage and ****py scaling, except the box.
He also needs to be tanky, something AP builds generally neglect, unless it's like a magic pen warmogs build.
And it probably wont get nerfed because it's rather easy to avoid before it actually sets up with any dashes.
I can see this ult getting nerfed soon