The Tiger King's Diary manga chapter 18 discussion

[Blackangel]

lol looks like the tiger spirit got a lot of cultivation years saved
and now he doesn't mind giving them to little ghost so that he could get a body and that's good.

 

[Rinko]

Yes and he had been cultivating them for a very long time.
It's not difficult to pile up so many cultivation years this way. Don't be too surprised about that Angel