What are ‘Armor Ruin’ and ‘Spell Ruin’

He's actually fairly easy when you use Frost Blade. Without it, every 2-3 attacks on the boss will make him use his counter attack, which is the fire circle that surrounds him. But with Frost Blade, this doesn't trigger, so you can attack him at will.

When he starts blocking your attacks, use a heavy attack to break his guard. He will then jump on the side of the room and then jump back in the middle to unleash his fire attack. You can jump approximately where he lands to avoid said fire attack, and then just spam your regular attacks again.

He will use the Fire Vortex 3 times or so during the fight (at fixed life values). To avoid it, go in one of the corners, and try to avoid the little lasers that will pop up. They pop right above your head, so move a little to dodge them all. You should have enough space in a corner to never get hit by those.

Rince and repeat and he'll be gone in no time. But don't forget to refresh the Frost Blade often.

The map is colour coded to show you which rooms contain locked doors. Locked doors require keys to open them, and there are a number of different keys to collect throughout the game. Keys are not consumed on use, so allow you permanent access to all matching doors.

• Skeleton Key (White)
• Library Key (Orange)
• Angel Key (Blue)
• Demon Key (Red)
• Divine Key

The orange legend for the library key doesn't seem to be very accurate; at least one of the orange rooms on the map actually has a Divine Key door in it.