Managed to beat the coliseum boss, Delphinus.
Probably the most arduous tug-of-war I’ve done in Neptune series ^^;
First, I obtained 4 神界の腕輪, the ring with the best defense stats in the game, which is a hidden treasure in パナンジャンル. The drop rate is very low, but I was lucky that I got my 3rd and 4th one close to each other.
Then I synthesized Uni and Neptune’s ultimate weapons. Nepgear already has her ultimate weapon from the holy sword ending. My last member is Rom for her healing skill even though I couldn’t get her ultimate weapon (the materials needed are beyond chapter 5).
Then I choose back-members that quicken next turn of action. I also use idea chips to hasten the next action. It’s a killer to let Delphinus get 2 turns to regenerate its health. Don’t have too many disks with level 5 yellow chips yet, so I make do with lower level chips.
But yeah, with this setup I managed to defeat it. I never cared too much about it before, but positioning the characters behind the enemy does increase the damage and quite significantly so. And I think this boss is weak against magic, I didn’t expect Rom, who doesn’t have her ultimate weapon, to deal so much damage ^^;
So I’m left with 2 trophies now. The 100 million G trophy and Nariyuki Dungeon mini-game. For the 100 million G trophy, it seems I can just lap around Trinity dungeon, symbol crushing the low level enemies (1 lap is about 600,000 G). It’s still a grind, though ^^;
I think I have an inkling on how to work on Nariyuki Dungeon mini-game now. Basically, as long as I already get all the equipments obtainable so far, there’s not really a point to move the floor up slowly (her level resets anyway). So just choose the right equipments, save before sending Stella out, keep my Vita on, and reload if she dies (especially once I’m done with the other trophy). And I can start playing PS3 game while this game holds my Vita hostage ^^;