Riot, Y you do this

Because terrain is terrain, it holds no allegiance.

She should only NOT be able to stun you against a piece of terrain that you can normally pass through. EXAMPLE: If Azir uses his ult while on YOUR team, you are able to pass through the wall, but Poppy isn't. Therefore, you should NOT be stunned, but she should be stopped by the wall, mid-push.

Oh. I didn't notice the champ icon for Azir in your discourse...erm. That is dumb if the Azir is friendly to you. She should be able to do it if the Azir is friendly to her, because YOU cannot pass through it. But if Azir is on your side, it should fail to stun.