I just wanna pick apart the problem with two of the current ideas for anybody voting, of course it's still your choice but it's potentially a big thing that could change your vote.
Option 1:
Similar to the SCAN Jammer, a "Demon Jammer" which would prevent players in its radius from being targeted by the Knight Demon, lasting for either a set amount of time or a certain number of uses
IN a lot of cases you'll find that the KDS will be used just to simply draw people out of the bank vault, the PD or the casino vault, which results in the instant end of the raid with the exception of the casino raid I believe. In these situations you are very unlikely to want to use a limited time item to prevent you from losing a small bank raid.
Another problem with this idea is that, if like the SCAN Jammer you cannot holster this item. Then you definitely aren't going to want to use this item in the long run, unless you are basing or nuking where it's guaranteed to be worth it. Whilst the idea itself is great, in most cases I can't see it working practically.
Option 2:
Before the animation, a short period of time where both users have a particle effect to give a small warning (allowing them to react by taking off suits, etc) before they are frozen and teleported
Simply this doesn't really change much, the biggest problem with the suit itself is that you don't get any chance to stop what is happening from happening. You are invulnerable (even to nukes) whilst being taken by the KDS anyway, so to be given the chance to de-equip any suits, becomes pretty much redundant as you get given a very large chance to get ready to holster a suit.
I would look at targeting the direct ability, rather than anything else about the suit. Perhaps make it so they have to be directly in your vision to be targeted (this seems mostly fair). Or look at another idea, but both of these seem to miss the point of the main problem with the suit.