Basic and Twin Crystals
I have an idea for two new types of crystals you could add to the contest. It would help address two issues.
Issue 1: As more and more and more champions get added to the Contest, it becomes harder and harder and harder to duplicate your existing champs. This makes it harder to awaken their signature abilities and harder to get the ISO you need to level up champions.
Issue 2: There seems to be a recent trend to make every new champion added to the Contest super super overly complicated with pages of text to read if you want to figure out their abilities. While this is fine, I guess. It's also potentially off-putting to brand new players just learning the game. There ought to be a learning curve.
So I propose these two new crystal types.
Crystal type one: the Twin Crystal
This crystal can come in 3*, 4*, 5*, or premium (2-4*) varieties. You can award fully formed ones or shards, and give them out as rewards in monthly event quests. Premium ones for beginner difficulty... 5* ones as rewards for special challenges, etc.
A Twin Crystal works exactly the same as other hero crystals, except that you are guaranteed to get a duplicate copy of a hero already in your inventory. Simple. If you get a 5* Twin Crystal and don't already have any 5* heroes in your inventory... either it can't open or it just gives you a random champion.
Crystal type two: the Basic Hero Crystal
This crystal can also come in different varieties.. 2*, 3*, 4*, 5* and premium (2-4*). Awarded fully formed or in shards. Each Basic Hero Crystal awards one of these heroes: Star Lord, Wolverine, Black Widow, Thor, Hulk, Black Panther, Storm, Spider-Man, Scarlet Witch, Iron Fist, Iron Man, or Captain Marvel. 2 from each class. Each of these heroes is strong, but also very simple and easy to understand. The real "entry level" champion.
I would suggest changing the awards of Summoner Trials to give out Basic Hero Crystals... or you could give some Premium Hero Crystal shards and some Basic Hero Crystal shards. Milestone rewards would give the 2* or Premium Basic Hero Crystal shards. And rank rewards for top 50 or 100 summoners could give out 3* or 4* Basic Hero Crystals, or 5* Basic Hero Crystal shards.
You could also put Basic Hero Crystals in the Beginner or Normal difficulty of monthly event quests, and maybe even insert them into some of the rewards for Act 1 and Act 2 of story mode.
This would be good for beginner players. They would get good, solid champs that they can understand how to play right off the bat.
And these crystals would probably also be sought after by veteran players... because some of these champs (Star Lord, Hulk, Wolverine, Scarlet Witch) are still some of the best in the game. But in the current game environment obtaining them, let alone duping them, is extremely difficult.