I would use rare candies. Or, train in Victory Road.
The easyest Pokemon is scizer and the hardest Pokemon is milotic.
Never mind, I'll ask again... Well the best way in Pokemon platinum if u want a strong Rhydon is to look inside the cave before the Pokemon league.
you fight your rival
Beat the Pokemon league again and go back to spear pillar and you will see dialga again.
In Pokemon league
jynx ..
no
go to the Pokemon league
Of course it can, golbat evolves into crobat if the friendship between it and u is good.
Just battle weaker but still strongish Pokemon until you are strong enough P.S. save before trying Pokemon league until you eventually win
no
they are in the Pokemon league.