“Pokemon Omega Ruby” and “Alpha Sapphire” reached ... Mega Slowbro - Slowbroite In the Shoal Cave, collect four Shoal salts and four Shoal shells and give it to the man asking for them.

(Nickname Regice while it is holding one of these items: CasteliaCone [obtained at Trick House], Snowball or Never-Melt Ice [found in Shoal Cave] in order to catch Regigigas later on) Regirock ...

At this point, make sure that you nicknamed Regice while it was holding one of these items: CateliaCone (obtained at the Trick House), Snowball or Never-Melt Ice (in Shoal Cave). If you didn't ...