u can't
stone pillar after beating Cyrus
serebii.net has a lot of useful hints that can help you out if you need info on where to find Pokemon :)
i think you have to have Pokemon diamond to get him or her whatever.
At the spear pillar.
Pokemon ruby's version IS Pokemon ruby.
you dont
spear pillar at lv.47
Arceus is not possible to find in Pokemon Ruby. It was released in 2007 with Pokemon Diamond and Pearl
You disappear and you reappear at the beach
Go to all the lakes after capturing diaga
You can find all kinds of pokemon.
You can't in ruby.