Shelder's evolution

It is all down to luck...equal chance at each moveset combo.

Good luck on your evolve.

Actually I'm struggling to get IS/BZ myself, caught and evolved a LOT of Shelders, but none with IS/BZ... still working on it :)

The moveset of the shelder doesn't impact the moveset of the cloyster it's evolved into. All you can do is evolve them, and then transfer them if they get garbage moves.

Movesets are selected randomly for all evolved pokemon.

I've been wondering if certain movesets have gotten more difficult. I used to evolve good ones pretty evenly but now it's pretty rare