I enjoyed the boss battle, although I think it would be interesting to have difficulty levels (either easy and hard mode OR easy, normal, and hard mode) available to players, and scale the rewards appropriately for completing a difficulty. This could also go in conjunction with making boss battles more stage-orientated, where you have to beat easy mode to unlock the next difficulty.
Besides that, one of the things I would like to see on the enemy general is his Bloodborne spell. Now, when playing against Calibero, you can tell by turn 2 that his BBS is “0 mana: equip a random artifact [Arcylite Regalia, Staff of Y’Kir, Sunstone Bracers] to your general”. While mainly an aesthetic opinion, seeing his BBS and being activated may clear up reasonings for him equiping a random artifact, or add another level of play to the fight.
I think Calibero should have a health increase, although this could be implemented in higher difficulties instead in order to make him easy enough for beginners. Similarly, I would like to see him have at least 2 types of spells (or more, based on difficulty) to punish the opponent for playing in certain ways (such as a healing spell and Atarauch’s tears, yet able to pull ANY artifact), and to add a greater surprise factor when playing against him.
Regarding boss crates, I think they are a fair price, as you get 3 orbs, a gauntlet ticket, AND a normal crate key to open a normal crate (which contains 3 cosmetic items), all of which costs more than $5.00, so I can understand why a time limit is placed on them due to the nature of this deal. If you add extra difficulties, I think you can get away with upgrading the key (rare or epic), adding more orbs or gauntlet tickets as rewards, and then raise the price proportionally.
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