Grand Assassin Ragano is the boss of the Tainted Laboratory area.
- Fine Blade
- S Rank: +3 Luck
- A Rank: +2 Luck
- Summons void-elemental traps which deal damage
- Goes invisible and reappears behind you
- Creates a void-based asterisk-shaped AoE around himself at low HP; has a wind-up time so can be dodged.
- Poison mist will slowly rise from the bottom of the room as the fight progresses.
- Summons Burning Skull (Green) during the course of the fight as his HP drops.
- Teleports across the field and sets traps whilst doing so
- Poison vats in the background will break and cause Demon Assassin (Green) to spawn as the fight goes on.
- You can remove the threat of poison by immediately jumping onto the moving platform at the top of the stage to access the floating mana machine. Destroying it will remove the poison mist.
- Despite teleporting and going invisible, this boss is very easy if caught in a combo. Knock-ups and catches can keep this boss stun locked, so he can be killed very easily.
- His void-based asterisk AoE will do a lot of damage, so try to avoid it. Void damage will also stun you, making you open for attack.
- Watch out for the Burning Skulls (Green) which can interrupt your combos.
- You can also ignore the poison mist completely by using an Antivenom Elixir, making this fight and the entire area very trivial.
Though he was never officially made a general in the dark army, many of the lesser demons respect and fear this self proclaimed "Grand Assassin".