To complete the main story quest “Taking the First Step” part 6, you can obtain the Koberinite as a drop from the Rock Puppet miniboss in the Sunken Mine. The easiest way to defeat it is by using Bombs to exploit the monster’s weakness to fire.

Before heading over to the Sunken Mine, make sure to complete these requirements:

1. Raise your Alchemy Level up to 6: In order to synthesize a Bomb, your Alchemy Level must be 6 or higher.
2. Upgrade your party’s equipment: By now, you should be able to improve your gear. Synthesize enough Ingots and craft new weapons for Ryza, Lent and Tao.
3. Synthesize at least two Bombs: Having an additional party member carry another Bomb will speed up the fight.

Upgrading Your Party’s Gear

Leveling up in Atelier Ryza doesn’t provide a significant stats boost. Instead, you will raise your party’s attributes by synthesizing better gear.

Head over to Ryza’s room and use the cauldron. Scroll down to the bottom of the list and synthesize new weapons:

• A Handmade Staff for Ryza.
• A Weathered Sword for Lent.
• A Stake Hammer for Tao.

The new equipment will give your party much better stats, making the Rock Puppet fight easier.

Synthesizing a Bomb

The Rock Puppet resists physical damage, but is weak to fire. Using Fire element items in battle and dealing magical damage is the only way to defeat it.

Bombs deal AoE damage so you’ll be able to hit both Rock Puppets at the same time.

Select the Bomb recipe from the list. At this level, you will be able to unlock at least two Effect loops and the Traits loop.

Prioritize the loops in this order:

1. The Effect 1 loop in the center. This will boost your Fire damage. Get it up to level 2 by adding two Crimson Ores, unlocking the effect Fire Damage (S).
2. The Traits loop. This will allow you to add useful traits to your item. Destructive, Rather Devastating and Critical are easy to get and will be a great help.
3. The Effect 2 loop. This will unlock the Lowered Guard effect, reducing the Rock Puppet’s defense.

Synthesize at least two Bombs with Fire Damage (S) and Rather Devastating or Critical. Equip the Bombs to Ryza and Tao.

Ideally, you would want all three party members to carry one Bomb each. However, this would require getting Lent up to level 12. Having two Bombs should be enough to clear this fight without trouble.

How to Defeat the Rock Puppet

Upgrade your party’s equipment and synthesize at least two Bombs. After doing that, take the boat and cross over to the mainland.

Head west of the pier, then take the path to the right once you reach the fork.

Keep going along the path and you will arrive at the entrance to the Sunken Mine.

Inside the mine, follow the trail and make your way to the lower level.

You will find a Rock Puppet standing still in the center of the map.

If you already have the Woodcutter’s Axe, use it instead of the staff or the Reaper’s Scythe to initiate the fight. Doing this will lower the Rock Puppet’s defense.

Start off with Ryza and use a Bomb.

Switch over to Tao and use another Bomb.

Keep switching back and forth between the two. Your goal is to take down one Rock Puppet and to stun the other.

Use this tactic and you will quickly win the fight while taking little to no damage.

After defeating the Rock Puppet, you will obtain the Koberinite. Take it over to Lilla to complete the quest.