Mana and soul cultivation

After that discovery, I have been practicing my mana cultivation like crazy. All of my savings are spent on buying mana crystals, and my jaw is literally hurting from eating so many of them. With the help of Escherichia Mirarcanium bateria inside my gut, eating mana crystal has become my quickest way of absorbing mana. 

Mana crystals are divided into five grades: E, D, C, B, A, and S, with their quality increasing exponentially. in terms of the sheer amount of mana they carry, one D-grade mana crystal is equivalent to ten E-grade crystals, one C-grade is equivalent to ten D-grade crystals, and so on. 

However, that doesn't mean an S-rank mana crystal is just a hundred thousand times better than an E-rank. No, in fact, it's ten million times better! 

Because how much mana the crystals contain is just one factor to consider. There are three other factors that come into play here.