- Boktai 1 has The Crying Witch Carmilla. Rather than fight her in the traditional sense, you have to bounce her own shots back at her with rotatable mirrors. Guess how easy that is, and it's made even worse since she can break and rotate the mirrors as well to mess with you.
- Boktai 2:
- Durathror is fought in brand-new, just got it, Black Django mode. You need to keep flipping from Change Bat to figure out where she is out of the multiple bulbs in one of her attacks, Change Rat to dodge the thorns in another one, and Dark Property just to deal good enough damage. If her bulbs break before you can find her, they release damaging spores that cover a wide area.
- Blue Dvalinn in the fourth dungeon. She just loves to stay out of your reach and pelts you with tentacles, spitting ink, and ramming. The latter must be interrupted with Spear attacks, otherwise it is unavoidable. The fight amounts to stocking up on a bajillion curing items and hoping you can last long enough to bring her down.
- One of the mini-bosses in the final dungeon is a large sea dragon, though the main problem is the arena you fight it in. The platform you're given is incredibly small and awkward, and falling off of most platforms in this game means Game Over. The dragon isn't terribly strong, but it does do a fair share of knockback, so you're likely to die quite a few times by ring out.
- Boktai 3's battle with Wings of Death Hresvelgr. You're in an arena surrounded by spikes fighting a boss who flies around and tries to blow you into the spikes with gusts of wind, and to fight back you have to grow vine platforms high enough to land hits. It wouldn't be too hard, but Trinity is tied up and helpless in the arena, so you have to keep him from hitting the spikes as well. It doesn't take much to kill him and earn you an instant Game Over.
- Lunar Knights has the fight against Baron Stoker. For starters, the stage you fight him on is windy, forcing you to constantly run towards him to even get in range. Get close enough, and you get an opportunity to break his defenses by attacking the elemental weakness of the claw he's using to guard. Fall too far behind, and Stoker will instead guard with both claws, rendering him untouchable, as he spams missiles at you.
The fight is more infuriating in the Boss Rush as you only get to use one character at a time, meaning that even if you get close enough to him you need to bear with his close-range attack until he switches his guard to the one you can break open. In this mode, his aforementioned missile attack will be prone to eating up a lot of your time, potentially damaging your rank and the rewards you reap from that run.
That One Boss / Boktai