At one point I had a lot of coins ( probably 4-5x the pay out of completing all the characters) and I was pretty confident I was going to level up all of my characters. Ended up with 5 or 6 diamond chests in the process and 10+ platinum just to find out that most of my XP was going into the 1,250,000 xp needed for the DIAMOND chest!!! Of course I lost all of my coins in the process and nearly made a dent to my characters. Suggestions, if anything, this Diamond chest should require less XP to obtain since Diamond chests aren't exactly the holy grail of leveling up your characters or increase the XP in the chests and offer some coins when opening them that scales to the players level. This takes way too much effort and resource just to get the characters to level up. My regret is that I should have just kept my 3 billion coins and waited for other events. This was not worth it.