The Zarken Defender has very high Defense, so you need to find a way to reduce it before you get knocked out of the battle. If you don't have Defense-reducing items/weapons yet, you need to go find them elsewhere first. Or maybe, you already have a few.
You can do this without relying on Yanfly.
First, have the skill apply a state to the enemy you hit. Also apply immortality (resist knockout).
Then, have the skill also activate a common event. Make sure this is ordered after the states.
Next, in the common event, check all enemies that are...
From my experience, the average player ignores buffs in general, regardless of their impact on the game. Sure, veterans like us might see their benefit very clearly when the damage numbers rise a great deal, but you cannot assume that most people are veteran strategists. Don't forget that a lot...
The boat is not in a town. The boat is on the world map, South of the Myssia, the town where Lilli joined you. It's right there, you can't miss it. That is, unless you rode the boat somewhere else and forgot about it.
A bust of my character, Lizzabelle, that I put together in GIMP. I combined the RMMZ generated face with my actual illustration of her. This is just me experimenting with busts. I don't really want to use busts in dialogue, but perhaps in the character menu.