If they have two +1/+1 counters and the creature gets one -1/-1 counter, youd remove one counter and be left with the single +1/+1 counter
Court of Emebreth might be the weakest if you arent the monarch since you only get a token, though it is a knight
Cloudshredder Sliver, Alibou, Ancient Witness, Thopter Engineer, and Karrthus, Tyrant of Jund are all excellent tribal payoffs
Since creatures matter so much for this mechanic, cards that remove permanents or otherwise impact the board tend to rank higher than those that don't, though the Court cycles are very strong since they play well with board wipes
Enticing new players to the game in drove, this set needs to be clear so prospective players dont get confused and give up
Yuna, Hope of Spira [Borderless Surge Foil] #549 (Magic Final Fantasy | Magic Cards) prices are based on the historic sales