Bone Mantis

The Bone Mantis is the guardian boss of the Gale Ruins in Grandia Xtreme. It is the last boss of Chapter One and can be found in the Great Engine Room at the end of the level.

Battle Strategy
Like all Grandia Xtreme's bosses it is ideal to remove the Bone Mantis's additional targets before ending the fight by destroying its main body, thus optimising potential experience gains. However unlike previous bosses, the arms have immunities: the left to magic and the right to physical, so you'll need to use whichever is the opposite to deal with them. On top of these immunities, all parts are immune to Lightning damage, which renders Evann's elemental-based moves useless. You'll typically want to use him for cancelling and pure brute strength here, but make sure to give him some offensive magic as well so he can help chip away at the right arm.

As the arms' resistances suggest, Fiora and Shhh! are the things you want to watch out for here. Having a stack of Move and Magic Blessings in reserve is worthwhile, but if you're on top of cancelling you shouldn't need to use them too often. Once you get rid of the arms, the main body will be able to use Wind Spear, which can inflict Confusion, but it's easy at that point to wail on the lone body so cancelling it shouldn't be a problem. Since it's a single target move, it should prove to be less of a problem than the Wind Slash move the arms use.

Though you shouldn't need to heal often in this battle, Myam is a mandatory party member for this fight in Chapter One and is useful for replenishing your HP in a pinch. If you're not using Jaid as well, she should be stacked with the best Mana Eggs. Carmyne and Titto are also pretty useful in this fight since they're quick at getting around the battlefield. If you feel you need the boost, the Land Cougars in the earlier areas of Whirlwind Peak and the Gale Ruins can drop Dash Charms (albeit rarely); it's worthwhile having a look for one, or using Titto to try to steal one, since 40+ MOV at this part of the game is nothing to scoff at.

Trivia
The Bone Mantis is very similar in appearance to Valmar's Claw in Grandia II. The two bosses also share a similar moveset.