enhance: improve gameplay after death in final boss

[64bitpandas]

When the player dies after attempting to defeat the final boss, they lose the scroll and are required to go back to the second arena and fight for it again. Maybe we should just let them keep it so they can attempt the boss whenever they want after unlocking the ability to do so (or, charge some other additional cost on top of the scroll so there's still some barrier but not too much).