[Cool story + no heroine + invincible + dungeon flow]

Change to become a summoner of the dead, and the skills can be upgraded once per second, and there is no upper limit for permanent upgrades.

[Small Skeleton Summoning] – [Big Skeleton Summoning] – [Elite Skeleton Summoning] – [Epic Skeleton Summoning]

[Desperate Skeleton Summoning]

[Scary Skeleton Summoning]

…

After N upgrades

[Skeleton Summoning to Welcome the Return of the Great Skeleton King]

In addition, there are [Hellfire Summoning] [Hellhound Summoning] [Bone Dragon Summoning] [Ghost Summoning]…

Skills are upgraded once per second, how do you deal with it?