Boss: Shinryu

Steal: Dragon Fang (common), Dragon's Whisker (rare)
Guaranteed Drop: Dragon Seal

Note: Dragon's Whisker is the strongest whip in the game.

This boss always starts the battle with a Tidal Wave, which can wipe out your entire party, and it also has access to many powerful spells. You won't last long if you fight it normally.
Shinryu has two weaknesses: it's susceptible to Darkness and Berserk. However, using Flash and Berserk won't be able to connect due to its high level and magic evasion.

Here is my personal strategy. If you've been following this guide, you should have all the necessary items/weapons. The idea is to go full offensive and kill it in 2 turns:

• Change everyone's job to Freelancer, set Rapid Fire and Two-Handed abilities.
• Equip Masamune, Enhancer, Enhancer, and Defender on everyone, as these swords can be two-handed.
• Equip Coral Ring on everyone to survive its first attack, Tidal Wave.
• During the battle, simply spam Rapid Fire and the boss will die in 2 turns.

I've seen many online resources suggest strategies that exploit its weaknesses, but this is too much work.

• Equip Coral Ring on everyone to survive its first attack, Tidal Wave.
• Use the Mix ability to mix Eye Drops + Dragon Fang to create Dark Sigh, which can inflict Darkness with 100% accuracy.
• Use the Mix ability to mix Turtle Shell + Holy Water to create Bacchus's Cider, which can inflict Berserk with 100% accuracy.
• Summon Golem to help block some damage and repeat if it wears off.
• Other allies can hit with their best attacks until you win.

Boss: Exdeath (Neo Exdeath)

He has access to all of the powerful spells in the game, including the ancient spells Almagest and Grand Cross, dealing huge damage and inflicting random statuses.
So anti-ailment equipment is a must for this fight.

And this time we'll need more preparation:

• 3 Freelancers job and 1 Mime job.
• 3 Freelancers: set Rapid Fire and Two-Handed abilities. Equip Ragnarok, Excalibur, and Masamune on them.
• 1 Mime: set Blue Magic, White Magic, and Equip Ribbon abilities. Equip Chicken Knife and Man-Eater.
• For armor, equip Ribbon and Hermes' Sandals on everyone.
• This time we need a support mage for healing and buffing.
• When the battle starts, the 3 Freelancers keep attacking using Rapid Fire.
• The mage should spend the first turn using Mighty Guard. The rest can be situational: if everyone has full health, you can use Mime to copy Rapid Fire, or heal using White Wind or Curaga.

Note: Ribbon is to prevent ailment statuses, and Hermes' Sandals provide auto-haste and prevent the boss from removing the Haste buff from your allies.