It's time to catch up with our side hustles. There is one important item here we want to obtain before finding Zinikr.

Side Quest: Money! Money! (Q-12) - Continued

Recommend Level: 33

If you haven't activated the quest already, teleport to En town square and talk to a man in front of Starry Eyes bar.

Warp to "Southern Forest - Kina's Old House", then move back to northwest area.

Preparation

Make sure that Leo has unlocked "Samidare (Fire)" and "Samidare Hit 1" because it's Leo's main damage skill.
Prioritize unlocking "All Potion L" and "All Potion+" for Ez.

This boss doesn't have any new trick beside it gets stronger than before, however, your level is also higher, and it should be an easy battle.

Try taking down Gold Fruits first whenever they spawn.
When the boss call its minions, use Ez's "Flame Grenade" to kill all of them in one turn.

(Optional): There is a small scene if you examine the Money-Money Tree.

Go back to the quest giver for rewards.

Recommend Level: 35

Teleport to "Ancient Hill -> Hill - Entrance".

From the entrance, go north on the bridges and continue to the next section "Nail Rock Region" (A).
Keep going until you see wooden boxes, examine the rob to go down.
(I-04) Iris Quartz: In the chest partly visible between boxes after you climbed down.
Go west, cross the bridge, to previous section "Entrance" (B). There'll find 2 items:
(I-05) Whetstone: First chest.
(I-06) Aquamarine L: Second chest.
Go back to "Nail Rock Region" (B), then exit through red pin on the left of the river (C).

This is where you fought the Golem before. Go on the bridge and continue north to the previous section (D), this time you are on the bridge.
Continue a bit further, you'll see a flickering object on the ground. Pick it up will initiate a boss fight.

This boss is an interest one. First, it is resistance to physical attacks.
Whenever you attack with an elemental attack, it'll store energies of that element then gaining resistance for it by half meaning you only deal 50% damage next time for the same element.
After hitting 3 times of the same element, it'll release the elemental attacks it stored at you dealing multiple damages. Then its resistance reset to 100%.
So the most effective way to deal damage to this guy is to take turn dealing different elemental attacks before same element hit 3 times. For example, you can attack with Fire, Lightning, Dark then repeat.
As you long you keep your HP high, you should be able to soak up the damage.

Teleport to "Frontier Town of En -> New District - Square", then go to the bar, and give the egg to Sid.