You will have every NB soon in this thread telling you how easily cloak gets broken and that there are so many counterplay options and l2p.

Yeah, I agree with you. IMO the best counter to cloak is the NB skill Piercing Mark because it's near instant and ranged. A good NB player will still be able to escape.

Edit: Just to clarify one thing, the NB skill Surprise attack will stun you if they flank you, not just from stealth.

Use that skill to find out if there are any stelth enemies when you get a keep in Cyrodiil.
When fighting NB in ​​battle, you can easily kill it by using potion or AoE.

Camo Hunter & Magelight have not worked properly for a long, long time. You're better off using an AoE damage skill to take nightblades out of stealth—it costs way less, does damage, and is more likely to actually work.

One of the best ways to learn how to hunt nightblades in cloak is to learn how to play one. Then you get a sense for where a nightblade would want to go, and for where they expect to be safe.

Meteor (Mages Guild ult) is another great anti-nightblade skill I use often—and stam players can use it, too. All you need is ONE second of sight on nightblades. They can't rolldodge it, but you gotta be ready to reach them and burst them down when the meteor hits in a few seconds. Some classes are better at that than others. Eye of the Storm (Destruction Staff ult) also works if you can be faster than the nightblade.

Sometimes the best way is to just wait for them to reveal themselves and overcommit to their offense. Use your heals-over-time and buffs, maybe block and be ready to roll dodge.

As a Nightblade who prefers playing without invisibility, I take a lot of joy in hunting down sneakblades in battlegrounds, but rarely ever use Magelight for it.