From KFM perspective, "clock runners" are the most annoying opponents in PVP. Any class that runs away more than 16m, please uninstall. BDs and SINs are notorious for this. Burn all skills then run. However, TOI is a different ballgame.
BD- resists and grab. They hardly do any spins, but that one resist skill is always up. They also grab you for full 7 secs and there's no way in hell to use counter "2" to escape unless you TAB. Yes, they run away often and only gets close when they stab you(stun) and aerial combo. They dont even do any damage. BD is probably top 1 time waster in my book.
SF- They spend most of their time 100 meters away from you. If you are one of those have no close gappers. Sorry.
SINS- This is 50/50 for me. They do sorta waste your time with the web thingy. BUT they go toe to toe during stealth which I find good for my end. They use lotus flower often, so keep doing aerial combos for more damage.
FM- Use KD against this class, they don't have a countermeasure for that. You will probably get most of your damage through ground pounding. Their grab and throw is ridiculously low CD. Yes this class is freaking annoying to go against with. I never find myself my frozen though.
Sums- Dont spend time killing the cat. Make sure you spec escape grab TAB. when you cc, make sure you hit both the cat and the sum. Always be ready to resist the cat call. It can be time wasting for Range classes because of the Petal Storm. Cat Grabs is low cd? For KFMs, we have HM LMB which helps reduce cd of our Second Wind. I use that a lot on the cat.
WL- screw that thrall suction. I use special build for WLs. WL dont usually stray away from their Thrall unless you CC them. I usually use my fire build here (aoe build). As long as I dont CC the WL, she will be in range for my AOE attacks. I have suction skills for backup.
This is a good tip for anyone: Always be the first one to attack, and immediately put them in stunlock. They don't usually use their tab, or backflip during the first 5 secs. This excludes SIN and SF so get ready to tech chase. Dont even try it against BD, they always use resist skill right away.
BD, SF, and SINs are my top 3 waste of time in TOI.