Ys Oath in Felghana Nightmare mode playthrough part 26 : Garland, The Dark Bishop

Alright, this guy is surprisingly easy. This time your best bet for dealing damage is your good old sword. Hacking away at him is fairly easy too, since he doesn't move around all the time like Chester, Death Faleon or any other boss did before.

First part of the battle, he'll keep activating a shield around him. As long as it's up, you'll be pushed back by some sort of wind. In this state, he'll use his scythe attacks. When he does that, he'll also throw energy balls that stay on the field for a while, so be wary of what's around you. He'll sometimes use his scythe above you, just staying on the ground will be enough to avoid getting hit. He will also throw a wave of white energy balls, which can easily be dodge by simply walking away, or with earth magic if you're too close to him. The last thing he'll use in this state are those lasers. They seem to be tracking you a bit, so keep moving, and earth magic if needed should do the trick. Note that he'll use the lasers and the scythe attacks throughout the battle, but not the white energy balls, for some reason.

To break the shield, a normal attack is all it takes. Doing so will knock you back a bit, and then you can close in to hack at him. When his shield is down, he'll throw lightning bolts at you that do a bit of splash damange when hitting the ground. Again, walk around while attacking him and use earth magic when it's appropriate.

After you lower his HP enough, he'll understand that his shield is completely useless and get a few new attack. First, he'll do a series of charge attacks at you. If you are positionned properly, you can just walk away from them. Otherwise, again, earth magic will allow you to block it, but it's risky. After doing this he generally reappears in front of you, allowing you to score some hits. When close, he might try to smash you with that gigantic sword on his back. It hurts, so try not to stay too close. When doing all of this, he'll keep using his scythe, his lasers and his lightning bolts, so it makes the field a real mess. Stay concentrated.

He has one final attack that he'll use quite frequently. He'll disappear and reappear in the center of the field. When he does that, get as far as you can, as quickly as you can. He'll try to drag you in, but assuming you have enough MP you should be able to resist with your earth magic. If he manages to get you, you'll be warped to some sort of weird space and he'll beat the crap out of you with his sword, in a way that is reminding of Knights of the Round from FFVII, seriously.

Final note, try to kill him with a fireball from a distance, or make sure you're ready to run away when dealing the final blow. When dead, he'll stay at 1 HP, then he'll drag you in before exploding. It deals about 200 damage, so it can easily kill you. It's cheap, yeah.

Now, to the final boss...