I think this needs a bit of a tweak now that magblades have taken pretty hard hits to every single one of their healing/defence skills.
I would like to see it become placable remotely so you don't actually need to run over to a safe spot every 30 seconds in order to keep a back door open to try to escape through.
This is not to say that it should become some instant "streak"-like escape in any direction, I believe it should be a given a short CD between placement and activation so that it still requires advance-planning to use properly but at least this way it could be easily re-positioned without completely removing yourself from a fight in order to do so. It's more of a quality of life change than anything.
Without something like this I think we're going to see every single magblade in heavy armor next patch to try to attempt to make up for lost healing & defences which just further contributes towards the homogenisation of classes.
Edit: a very good point made by another poster below. It must also not be possible to place the shade on ledges and walls above you to prevent bypassing keep walls. You could make it a small ground-targeted AoE that requires full-LOS to place, that would address that issue.
Edited by lucky_dutch on October 3, 2018 11:15AM