Head to Rusturf Tunnel which is east from Rustboro City inside use Rock Smash and talk to the karate guy he will give you the HM Strength.
The HM04 Strength can be found in Rusturf Tunnel in Pokemon Sapphire.
To get regirock you need to have a pokemon that knows strength or rock smash,(his place is in the desert area
There is no Pokemon mansion in sapphire.
He is not in Pokemon: Sapphire. You will not be able to find him. He is in Pokemon: Diamond, Pokemon: Pearl, and Pokemon: Platinum. You will definitely have trouble finding him in Pokemon: Sapphire.
unova
you can't find it in Pokemon sapphire, but you can find it in Pokemon ruby. Hope this helped. :-)
Lucario isn't in Sapphire,Sapphire is a Hoenn pokemon,Lucario is a sinnoh pokemon.
strength
no you cant. you catch spheal in Pokemon sapphire and snorunt in Pokemon ruby.
I'm sorry but you can't find a diglett in Pokemon sapphire, you can only get it by trading
There is no mist stone in sapphire.
use strength