So far THE WAVE BROOD -note the CAPS :)- is one of my favourite cards in the Chaos Legion set.
Why I think is a good card for invest?
The gold foil is around 100CP/USD, so I can get some nice airdrop points still for 100 days and get some dec back on my buys renting the card.Playability
The Taunt is really nice. All enemies cards must attack this one, it has reduced damage against magic attacks, and also you can put it at the back with a tons of CL healers, or in the front with a Kelp Initiate/Merdaali Guardian. Is a really nice tank with 12 HP for only 8 mana, and also with Keyla it has a +1 Shield, extremely overpowered.
Final thoughts
If you want to advance in leagues Keyla/Wave Brood is the way to go in the CL expansion until new legendary summoners come out. Even if you dont want to play that much, you can rent the card for a nice RoA with #peakmonsters, and most of the useful cards in Untamed -epics- go way lower in terms on CP/USD. It will take a while, but pretty sure 40-50$ per Wave Brood BCX is closer to its real value. Dont forget to buy some until its too late :)