After paying the koins and hearts/souls or whatever to go through my chosen character's tower, the grind hasn't felt nearly as bad to be honest. Instead of having the Noob or Liu Kang AI grind for me, I've been practicing combinations, krushing blow combos, and so forth while collecting the mercies, brutalities and whatnot I need in order to progress and unlock more customization options for my characters in the towers of time.
While doing that, getting flawless victories and using konsumables to make fights even easier and go by faster, I've been getting enough koin to unlock a majority of the chests in the krypt.
My major gripe isn't so much the grind now.... It's the fact that a majority of the skins are actually just different shaders for the same skins or even 'alternate' colors... I.E basically half the skins are simply the P2 alternate colors you could EASILY access by pressing start when you select your variation. I find that tidbit kind of annoying. I want to unlock legit actual skins, not color reskins... especially alternate reskins for skins I already technically have.
I also wish I could choose or view the end of round taunts my characters use. There's a lot of them, and some of the ones I've seen are kind of lame compared to others.