I want to start by saying that I am going to be talking about the financial aspect of the game, as it is a 'Free to Play' mobile RPG, as well as the game itself separately. I do this in part to give the actual mechanics of the game a more fair review, and in part to explain my frustration with this game.
This is an RPG where you are gathering champions by summoning them from crystals and using them to fight either in the Arena against other players, the story campaign, various dungeons, and a few other things. All of which are built around the same combat system and this is where the game does become rather engaging.
See, there is an incredible number of champions with a good variety of abilities. Throw in some fairly simple 'This type is strong/weak vs. This type' of set up for the champions, and you honestly have a very robust system that can require a lot of thought and strategy into forming your party, as well as a vast amount of ways to set up your party. While the combat system itself doesn't do anything unique, it is a very strong foundation that the game can do a lot with.
Being able to gather so many different champions with so many abilities really is the main draw here, and it's a possible interaction between champions that make things fun. Example, my current main team for clearing story missions includes two characters with great attacks that hit all enemies, the fastest of the two inflicts group debuffs to defense, speed, and attack, my second one having a higher damage output. I pair them with a leader that boosts my group's speed with her aura (A Passive Buff that takes effect when a character with one is set as the leader), and the fourth champion with a decent group attack that boosts the speed of my team, and another ability to move my allies turn order up. Simple strategy for dealing mass group damage in a very short period of time.
There are even plenty of ways to customize all of your champions. Other than straight power ups like ascending your champion to boost stats and upgrading your skills to make them stronger, the gear you put on them effects their stats differently and you can choose which mastery paths to go down, which can affect both your stats directly or add in small and useful passive abilities such as increasing damage versus shielded targets, or recovering a small bit of HP whenever you fell an opponent. The same champion can be used in different ways as a result.
That said, I like that you have to change things up for various bosses of the story mode, or even the many dungeon bosses you can fight. Making use of a variety of champions, you can start to put together specialized teams for different situations. Faction Crypts have you using heroes only of certain factions, limiting your options for certain challenges and forcing you to adopt different strategies there. If I were to look at this game purely on its mechanics, I'd go so far as to say it's fantastic. But now we get to the problem with the game.
Once you start getting characters up to the fifth rank, done by sacrificing champions to raise the rank of other champions, the game starts to grind to a very slow crawl. As is the model of the mobile RPG, this is to encourage you to have to pay money to more easily move forward. As the game itself is free, I can understand the model, but let's look at what you get for your money, and I'll do so by using one of the packs that were made available for purchase for a limited time. Here is what you get.
Three Sacred Shards, each of which gives you a chance at a Epic (Starts at Rank 4, more abilities then lower ranks) or Legendary (Same, but Rank 5) champion.
Seven Hundred and Fifty Gems.
One and a half Million Silver.
Now, the main thrust of this game is gathering champions, so while Gems can be used for other things, I'll assume we are using them to buy more shards to summon champions to gauge the value of this pack, and that amount is effectively worth nine Ancient Shards, which have a chance at a Rare, Epic, or Legendary. Rare is the most likely pull from that and is a rank three champion to start.
So you get eleven chances at champions, repeats are possible. Also, not all chances are created equally, meaning you could get some champions that are just bad, even if they are epic or legendary. Nine of those are most likely going to be the lowest rarity of the bunch, though you may get an epic or legendary from the ancient shards if you are lucky. The money is nice for upgrading gear, though each upgrade past the first couple have a chance to fail, I have lost a close to a million silver trying to get a single upgrade before.
So for all that, you are paying seventy dollars. For so little, you are paying more then you would pay for a full-price video game. And yes, there are some terrible value AAA titles out there, but short of some of EA's horrible price gouging practices with Battle Front II at its launch, even those offer more for your money than this pack. Effectively all it does is allow you to slowly move forward the current state of your game. I admit I don't have a lot of experience with mobile RPGs, and only tried this out when it got a PC version as I hate gaming of a phone screen, so I have no idea what is and isn't normal pricing for these games these days. But in no way can I justify these prices.
It's a shame because the game has such a strong foundation to make a legit great game. The mechanics are there, the visuals are fantastic, and there is plenty there you could potentially build a good story around. But this pricing model and necessary slow down of progress used by the Free to Play model of game kills it dead in its tracks. For the price of that one pack, I can find you three fantastic games on Steam/GOG, each of which come with far more content than that seventy dollars gets you access too, as well as leaving you plenty of money left over for snacks while you play.
Unless you have an incredible amount of patience to avoid spending a lot of money on this game to progress, I can't recommend this. I hate this whole mobile pricing model, and I hope that Raid isn't reflective of how bad the whole thing can get, and is just an outlier.