All Lania’s are immortal, they can’t die, instead they will became an egg again and rebirth stronger thereafter. "You can do a manual rebirth if you don't like your current Lania!" :(
You could make it so enemies sometimes dropped the energy potions or a gem. Maybe make it so that you could break down evolution monsters, like cauterclism volcano king into five coals or orecore into 2 ores, Etc. An option to unevolve monsters would be good too.