I do also have one other criticism, it's about the remove dice option.
I totally understand why you nerfed it, getting rid of 3 dice in one go was extremely useful, but it is now horrible to use, it either needs to be 2, or you need to start with less dice.
Upgrading is pointless until you knock them down to at least 2 each, you'll never pull said upgrade enough to actually assist you when it's competing against 2 non-upgraded, and if you have 3 of only one chances of you pulling all of 3 of said one, and only 1 of either of the others (dependent on if your heal is out or not, which can lead to you being forced to waste it), is too high a risk, because chances of it repeating the same pattern multiple rounds is pretty high, and I'm speaking from the experience of pulling 3 rounds where I only pulled boosts and defenses because I decided to try and grab a new dice and the only good one was a def-die, and had gotten rid of an attack a round earlier so I had a better chance of pulling my upgraded one.
This also means you can't add a die unless your collection of the type it's a part of has less than at least one other, especially if said group is at 3 or more, because then you might only pull said die, which will pretty much be an instant-kill on you dependent on both round #, how many of them are higher than basic, and what you pulled (i.e. shield maybe you can block, attack maybe you can kill, but boost or health you can't do anything, and the latter makes you waste all of them if they're crystal).
And to even focus on removing dice can take up to 11 rounds to even be able to remove 2 because of said balancing issues meaning you either pull all of your boosts or all of your attacks, either of which means you're going to take damage, and dependent on how many enemies you have, and what types, means you have a very high chance of losing enough HP you have to sacrifice balancing with a remove to heal instead, and then it repeats because you're now a round higher and the enemies are stronger, unless you just outright die said round because you only made back 10 of the near 20 HP you lost during a round where you were full health.
Also, this is a pretty good example of why you can't add dice until you've both removed enough, and also upgraded what you had:
