► Playlist with playthrough: • [DS] Megaman ZX Advent
Boss: Pandora and Prometheus - 03:32
The Undersea Volcano isn't anything special as far as I see, there's some annoying bits with falling rocks and Chronoforce all but trivializes this part. I went with Model L just to for something a little different here.
I did play very cautiously with Queenbee and Argoyle forms here to deal with some segments because I was sick of taking damage in spots where I used to blaze through it like it was nothing.
The boss fight on the other hand is very interesting. The duel against Pandora and Prometheus is pretty fun and has many ways to be tackled on.
I went for the standard Model A approach to show that you don't really need the other Models or forms to deal with them, but in my previous attempts I remember using Model H and Model F a lot to avoid some of the combination attacks these two may throw at you.