The Chimera has very high HP and possesses a range of powerful elemental spells. It also uses the ability Paralyzer, which often hits its mark, paralyzing one character. It tends to paralyze two of the characters then proceed to defeat the third, still active member of the party, which results in a Game Over. So when Paralyzer hits, it is crucial to cure the afflicted party member right away, so one does not fall victim to the aforementioned strategy it likes to use. Having any of the Elemental Rings (Fire, Frost, Thunder) helps reduce and remove any damage from its wide range of attacks.
In order to defeat the Chimera, Ryu should use Accession by using Force, Gross, and an elemental Gene so that he's immune to that element. Proceed by using Focus and Aura every chance you get to quickly take sizable chunks off of Chimera's HP. If Momo is in the party, she should use Might on any offensive character (including herself), and, if she has it, use Shadowwalk to inflict good damage. She can also function as a healer if needed, since Ryu will probably be devoting his AP to Aura. If using Rei, have him transform into Weretiger so that he'll inflict constant damage each turn (though Influence is a must for this strategy). If one does not use Weretiger, then have Rei use Speed to boost the team and follow it up with physical hits, using healing items if needed, since his naturally high agility allows him to outrun Chimera. If using Garr, stick to physical hits, though using Gambit can inflict some hefty damage if it hits, which helps whittle Chimera down faster. Throwing in a Focus before each attack can increase the damage output. Nina should use Myollnir, Magic Ball, and Mind Sword for the best results. If she has them, use Shield, Barrier, and War Shout first to bolster the team and use healing items such as Whales and Spearfish (the former of which can easily restore the party AND heal any paralysis). If using Peco, mainly stick to physical hits, but using any of his breath attacks can help deal some good damage (Dream Breath can be particularly helpful, as it can put Chimera to sleep, granting the team a free turn to either heal, boost their power, or attack without retaliation). Since Chimera has no elemental weakness, the best strategy is to just constantly chip away at it with strong, reinforced attacks, healing and removing paralysis when needed, and it'll go down.
