I’m not sure how I feel about this.
In a way I think it’s a good idea, especially for f2p and c2p who don’t buy any big offers which usually contain the 4s items. They are more likely to keep up with the meta and the slow powercreep that comes with new heroes.
On the other hand it would make the strong even stronger. Because now they can easily have multiple of the best heroes in the game. I know some already do, but this will allow more players to do the same. For example: Someone has a leveled Domitia. He or she is fortunate enough to pull 2 Kageburado’s, but only has the mats for one. Kage is (in my humble opinion) ways better than Dom. He/she levels the one with the materials available and uses the token to reset Dom and pump it all into Kage #2. Now he does not only have a leveled Kage, he has a second one basically for free (the mats, hams and feeders have been spend on Dom earlier, so eventhough it “hurt” back then, it feels like a free hero now).
Conclusion: the core of the idea is good, but it will need some tweaking before it can be a balanced addition to the game. I for one, wouldn’t want such coin to be available for purchase, but rather make it a very, very rare drop (0,01% maybe?) on rare Titans and rare Titans only.