User blog comment:Lord Loss/Discussion of the Week: Returning Monsters/@comment-4009941-20140804183834

Velocidrome should have said "MH1 > MHP1 > MH2 > MHP2 > MHF > MHFU > MH4 > MH4U"

Lavasioth got a lot of changes. For example his size is much small, he is more stubby, he attacked from underground when exiting lava and his color was more dark.

They already gave reasons why so many monsters returned also. Fans missed their fav monsters(Japan not everyone else), The game takes place in Old World locations as part of its story mode, and they even had fans pick some old monsters to return asking the public directly in polls. If there was not old monsters returning it would look weird after all the maps they made also like 7 years ago which the story is based on.