So you get really far in to the catacombs and you find your self in a reaper room filled with bats skeletons and slimes, and the leveling orb is just right there. So you make a mad dash for it and boom, Reaper spawns you know you are ill prepared and there was about 5 enemies in the room you panic and then boom dead one shot. Are you tired of this? well i got a few solutions to help with this.

For any class you will need only one and that is an:

Ice Potion
this magical item will save your life almost more so than a health potion (not really)
why an ice potion? Little known fact reaper is not immune to almost anything and that means ice encasment too.

Optional

If you do need any other suggetions some would be:

Potion of Might
In addition to ice potions, potions of might will get the job done faster. Like the battle would last 5 seconds and boom the deed is done.

Health Potions
If you do seem to be running low on HP always-Always keep your HP full especially if the boss is beeing summoned in a room full of stuff.

What spells you'll need

Ice Spell
Just like in the potion section you will want to encase the reaper, they are that affective yes.

Optional

Here are other helpful spells for you

Heal Spells
Just like the rest HP Is top priority

Undo
This is my favorite spell it acts like a one up. You do not know how much this thing saved me (10/10 would rewind again... sorry)

Magic blast
for those who dont have alot of strength like e.g Poet this can help alot especially with high MAG, though I would cover that later

Teleport
If for what ever reason you dont want to fight him at all, use teleport. It can move you out of the room.

Slow
This is very risky especially since it is a close ranged spell I will only recommend this for lasting effecting time on the ice spell/potion.

Break
This is just for the room it's self if it is cluttered with bolders and such use this to at least remove some of the crap in the room.

As for this section I do suggest on getting

STR
Bully's greatest stat level this skill a good amount and dont for get to pick up
Focus Strike build the damage with a might potion it can go really high

SPD
Really good with juking the reaper dont forget also
Freerun auto evade is good as well but careful with wall running it may seem cool to dodge the reaper when running up the wall but it may just kill you.

MAG
Poet's stength lies in his magical ability.
Over load can be awsome use it with your ice or any spell for that matter

Optional

INT
Since it does give you a longer lasting potion effect using it with the Potion of Might is the best.
Trajectory this is good if you want to throw something at the reaper but you are scared to come out of your hole.

Let's talk about the room for a bit depending on your room your strategy can change.

Big Rooms
now they can be good and bad good because you have alot of room to work with so you can run around avoiding the Reaper. That being said there may be alot of crap that are contained in these rooms be that of chests boulders or tourches it will be hard to run around these things so stay alert.

Small Rooms
Now these in my experience is an instant death trap very little room to work with here. But it does have very little to no items in there so movement is all the more important. Otherwise ice encasment needs to be done all the quicker.

Holes
if you are lucky there will be holes or little gaps in the room dont be afraid to use them they are your friend. The reaper has almost no way to reach you.

Traps
Most big rooms have traps and the most affective traps are falling weights, use it to turn the tide, they are very use full on the reaper.

I have used the ice strategy on reaper many times and it always turned into my favor. remember this game is in alpha so things are subject to change. I may update this guide if I find more effective ways to deal with the reaper. But hey it's a game and games are made to be fun, so go get at it and have fun in the catacombs....kids ;)