So I've been playing standard format joust games for a while now and two characters stand out as REALLY powerful.
Brienne of Tarth (ITE) - While Brienne of Tarth is participating in a challenge, opponents cannot trigger effects.
She seems especially powerful in a Military challenge on the attack. They can't save, remove characters from the challenge, boost their strength, etc. You can do all these things and play cards like moment of glory or trigger abilities which they can't cancel!
There only seem to be a few decent ways of dealing with her other than with a targetted kill: Milk of the Poppy (and other in house attachments) and Ramsey's Betrothed. Both are pretty easily dealt with themselves as in a Stark deck the stalwart Arya Stark is very popular and Baratheon have great attachment control through Stripped Of Honors.
The only passive effect I can think of that affects the situation is Nestor Royce's ability, which will only help if they have more lords/ladies/nobles than you.
Lannister have plenty of good kneel effects but this one just seems to have so little cost. For the ability to kneel their strongest non-immune character each turn you don't pay much. He's not understrengthed, gets two icons and in standard there is only one card worth using that hurts allies: Ser Arys Oakheart. He's non-unique so you can run 2 or 3 without having dead cards in hand and if they steal him they generally won't be able to use his powerful ability. So you get a slightly weaker character than otherwise in return for kneeling the character of your choice each turn. This guy burns me on a regular basis.
Do you guys find these characters incredibly strong too? What do you use for counters?