It's a remake and a sequel (i.e. they included a remade version of the DS remake of The Lord of Elemental with this game; now it doesn't look like shit anymore).
To put this in context, while that last attack will pretty much wipe Cybuster for the rest of the stage it's roughly powerful enough to one shot the final boss with. And even without the spirit fusion it's still a beefy attack.
Damn this looks incredible! How in the world do you guys manage your way through all the japanese language in these games though..... If there is some secret that I don't know about that would enable me to play these games (short of learning a new language) I would love to be enlightened... Do you just use translations you find online?
Mostly, we don't. What we do know however is the general layout and mechanics that the series tends to use and can figure out the rest through either context or from online information as well as the general scheme of the plot (or plots in the non OG SRW games since those are based off of the series being included) based off of various synopses including other games and other media.
The two GBA OG games were released in the states and the translations of the other various games such as SRW 1, 3, @G, and J are the best ways to acquaint oneself with the series involved as well as Wiki'ing the various Gundam series, as well as a general synopsis of Mazinger and Getter Robo for the gist of the non OG games. There's also an anime version of OG2 that recently came out in Japan called SRW:OG2:The Inspectors, although I wouldn't recommend watching it without foreknowledge of the game since it condenses things a bit too much (though it's leagues better than the other SRW based animes out there).
That said, one thing to remember about this game in particular is that it's more like FFT/TO than the usual SRW game is (i.e. not really at all) in that placement and flanking are actually important (and possible) in this game.