Strategic complexity This is not only fine at common (provided it doesn't have one of the other two types of complexity) but encouraged, as it helps to create depth for the more advanced players
Aang, Swift Savior is the biggest hitter so far, selling for between $1,600 and $2,750 on TCGPlayer, with current listings pushing the range to $1,900-$3,500
Murktide Regent is an absolute monster that can easily shut down a game once it enters the battlefield, and the nature of the card means that you'll probably have at least one counterspell to protect it once it's out
A few copies of Fertile Footsteps turns Beanstalk Giant into the most broken ramp card of all time
Theyre also really good to build around if you wanna take them out of your deck (especially Gandalf and Radagast)