It's been about a week since the launch of new Chaos Legion reward cards. While the playerbase is still in the discovery phase of what new cards work well with others, it seems the CL card prices are trending lower as supply rises. Although, this is premature to assume because as seasons near an end the rental market and card prices may heat up. One card to me, that sticks out while playing bronze, is Venari Wavesmith.
Wavesmith seems to pair well with Alric Stormbringer due to being magic and providing armor protection to the low health mages in the water deck. Alric Stombringer is fairly pricey at about 80$ for level 1, but is included as a starter card anyway. So players can just snag Venari Wavesmith and do well with only starter cards.
While magic does do well in the lower leagues due to ignoring armor and not dodgeable, it's only counter is magic reflect and void. Owster Roswell would counter a pure magic build and the earth deck includes Failed Summmoner to do magic reflect. These counters seem minimal if you just wanted to passively spam Alric+Venari combo for wins.
On a final note, glancing over at the market prices, Venari Wavesmith sits around 4$ and will rent lowest around 6-8 DEC per day. According to PeakMonsters.com that's nearly 300% yearly return on card price if demand holds rentals up.
Disclaimer: If I sound like I'm shilling this card, it's because I decided to buy a few and rent out anyway so I am biased.