@Stalkerman The Tower has 3 powers: Magical, Holy, and Divine
Magical is used to summon monsters
Holy hasn't been explained yet
Divine is construction.
The transfer rate between them is
1 Magical = 1 Holy
1000 Magical or Holy = 1 Divine
In order for him to properly make the tower a successful base he needs more Divine power. A freaking bath costs 10k Divine power. A teleportation Gate also costs 10k. Hell, even a small outdoor structure costs 10k.
Magical and Holy power is absorbed from the tower's natural environment.
Divine power is absorbed from the death of summoned monsters inside the tower. Natural death gives you little, killing gives you lots... but it's based on the strength of the monsters -.- essentially, it could take 1000 slime kills to get you 1% of the way to your 1 divine power point.
In order to speed up his Divine power production, he's making plans of developing an adventurer town inside the tower and have them take on the dungeon floors. In order to get there, he'll make a convenient gate at their town since even getting to the tower was originally a horrible task by itself, and then tax the gate to make some money.
Unfortunately, this plan kind of had a loose knot in it; the adventurers of the continent he's on are all mid-level and above! what mid level adventurer wants to chop through 30 levels of slimes and skellies before finally getting to the good stuff? So he originally wanted to perma-shift the tower's floors around so that it would be more enticing for the continent's adventurers. Since it was too damn expensive to shift entire floors, he made a special gate that could warp mid-level+ adventurers straight to level 40 instead. He then planned ahead and made other warp gates to section off the tower.
For a foot note, each level is connected to each other, naturally, through a portal. There is no actual environmental exchanges between them.
PS: Mitsuki's teacher outfit = yes