First off, you want to rescue all the villagers otherwise this fight will be useless and
you won't get any further in the game. Now first off, if you aren't prepared for this
battle in terms of items like potions especially, then this battle won't last long. 

Now first off, you need to get these two glyphs, Vol Umbra, which you can find in the end
of the room directly opposite the save point leading next to the Boss door, now this room
is blacked out so I advise you to just slide underneath all the spike traps and jump the
walls you hit, now when you see the glyph there should be a small bit which you can stand
on to absorb the glyph after this the room will light up and you can see all the walls. 

Another glyph that will do you good against Albus is Vol Luminatio, you can aborb this
from the enemies outside the save room. Now if you've got Sapiens Fio that'll give you
some more of an upper hand against him too. 

So now you've got your glyphs, make sure you've got maximum hearts, because you're gonna
need them to end this quickly. Equip Vol Umbra and Vol Luminatio and Sapiens Fio if you've
got it. After this, save and go on in. Now after the cut scene you'll start fighting him,
most of his attacks are easy to dodge, but some of them can catch you out. 
1) His standard gun attack where Albus is quite straight forward, just jump behind him or
duck and use this chance to use Vol Umbra as this will do the more damage of the two
glyphs but if it doesn't reach just use Vol Luminatio. 
2) His secondary gun attack, which you can tell he's about to use it by him saying
something that sounds like "Vertical shot". Now this attack is a bit harder to
dodge, you ideally want to get behind him and fire away your Vol Umbra.
3) His glyph gun attack is quite handy because you can absorb it and that'll give you 10
more hearts which is very handy. But if you don't get the chance to absorb it when make
sure to jump over the bullet, which is large and orange, otherwise it'll do some harsh
damage and curse you, which is bad. 
4) His kicking attacks are the ones you really want to watch out for, because if you've
got about 39-44 def it'll still do about 140-180 damage. These come in two forms, a
straight up vertical kick which usually comes about when you stand right next to him for
too long. And the long curved kick, which can get you at the worse of times. He also does
a sliding attack, which is the least of your worries.
5) He also casts topor sometimes, and this goes about half way across the room, you can
see where it's gonna go so it's easy to dodge.

Now that you know about his attacks you can start thinking up ways to get it to work to
your advantage. The Vol Umbra Vol Luminatio special attack works really well against
Albus, and this is where his glyph gun attack comes in handy. The special attack takes up
50 hearts so if you're on about 0 you can get it up by keeping your distance from Albus to
provoke him to use the glyph gun attack. Other than that you really just have to use Vol
Umbra as much as you can, if you can his him when he shoots one use of Vol Umbra will hit
twice.

Carry this on till he's dead, and use potions if you have to obviously.