talk to heatran and battle it
It's at Manerny Lake/Beach west from Enermy Town. There should be a gym leader there from another region. Talk to him and he'll give you Lava Surf. (I couldn't find a really good Pokemon that could learn it though.)
no Pokemon hold lava cookie but you can get it from the lady in lake valor simply find her key(with a Pokemon with pickup ability) then go inside and there you go she gives you a lava cookie
you can find moltress in Pokemon deluge in map 10 the lava map.
In the royal unova
Same problem here lmk if you figure it out
well put rock in lava, but on the place where you have 2 rocks put the uper one
You would find him on firecave lava cave.
map 10 lava map
Lava Plume can only be learned in newer and more recent game slke platinum diamond pearl soul silver heart gold
it's only avalible in Hoenn region
after catching heatran, go back to stark mountain and you will see groudon in the lava and when you go up to the lava groudon will come to you like he does in R/S/E and the battle will start.