My experience with the original release of AERENA - Clash of Champions is fairly limited, but from what I'd played it seemed like a fun turn-based take on the MOBA.
There are over a dozen unique, specialized characters for you to unlock and pit against each other, all in the name of earning enough money to unlock even more characters.
AERENA - Masters Edition is more or less the same game, really. Only it's not free to play.
A curious assortment
Each match in AERENA has two teams of somewhat bizarre characters squaring off in a small arena (see what they did there?) while trying to destroy their opponent's airship.
The ship can be damaged either by direct attack or by eliminating enemy characters, and once a ship is destroyed the match is over.
The game actually plays somewhat similarly to chess. Once you spend a character's two actions (moving, attacking, using specials, or firing special shells from the airship) it's then your opponent's turn.
This alternating between sides and characters forces you to really think about your movements, but you're also on a timer so you really can't think too terribly long on it.
Brawls well that ends well
This premium version of AERENA is almost identical to the free version, with the exception of how it takes you to access and unlock new stuff. And there aren't any ads.
You'll still begin your game with three heroes, but they won't switch out as they do in Clash of Champions. It also doesn't take too many matches to start earning enough money to recruit new characters.
Setting aside the premium/freemium thing, AERENA - Masters Edition is a perfectly enjoyable strategy MOBA-thing in its own right.
The only real issue I have with it is the ridiculously tiny in-game text, but once you get used to the iconography it's easy enough to just ignore it.
I can't claim that this version of AERENA is really better than the other, but kudos to Cliffhanger Games for giving their players a choice.