ability to expand monster storage
If you played long enough, then you will probably have most of the epic monsters. Now, you need to stock 1-2 extra to upgrade.
Then you also need to train like 5 monsters to lv 50 to get legendary monster.
On top of that, you also need to stock quite a few slimes for quick upgrade.
Can that be increased to 120? If not, at least give us a way to increase the storage size like what you do with inventory.
Maybe increase by 2 each time. Maybe the first 5 expansion can be done using silver coins. Then using gold coins afterward.
Thanks