I have a question regarding my X Nuzlocke run. I lost my Meowstic against the 5th gym leader (damn Heliolisk), so I need a replacement.

My core team is:

Greninja
Talonflame
Ampharos
Snorlax
+ Diggersby HM slave (Cut, Surf, Rock Smash, Strength)

Reserves:

Golett (witk Klutz)
Combee (male)
Rhyhorn
Hippopotas
Slowpoke
Mr. Mime
Stunky
Drifloon


Which one would you use to replace Meowstic? I was thinking about using Mr. Mime, since Slowpoke would mean a type overlap.

I'm also considering boxing the HM slave (since I don't need it always), which Pokemon would you add in this case?

Thanks for the suggestions in advance.