Fireballs are supposed to destroy lots of blocks but break like two blocks and do a lot of damage. They need to be like hypixels fireballs (maybe a bit smaller explosions) and break maybe a diameter of 5 terracotta blocks. Also remove the cool down, because they are already so hard to get, because if you miss you cannot shoot for 30 seconds. The explosion radius (like where it can damage players) is fine just make it destroy more blocks. (I mean blastballs with this post btw)
Hope you having a good day
