Dark Realm

The Dark Realm can be entered by speaking to the Dark Enchanter found North East of home.
To enter the Dark Realm the Dark Enchanter requires you to bring him some items that can be found on the list he gives you after speaking to him.

Broken Seal
The Broken Seal can be obtained from the Dark Enchanter in exchange for 1250 viserion souls.

Viserion souls can be obtained from killing npcs with 500+ HP

500-999 HP: 25 Viserion souls

1000-1999 HP: 50 Viserion souls

2k+ HP: 100 Viserion souls

Alternatively the broken seal can be bought for 400B from the Dark Enchanter.

Evil Matter
Evil Matter can be obtained from the Dark Enchanter in exchange for a piece of the Shadow Torva Set.

Alternatively the Evil Matter can be bought from the Bill Ticket Master for 200B.

Angel Plasma
Angel Plasma can be obtained as a drop from the White Gelatinnoth Mother found in the Gelatinnoth Minigame (1 in 15 chance)

Alternatively the Angel Plasma can be bought from the Bill Ticket Master for 200B

Dark souls
The last item required is 1250 dark souls.

Dark souls can be obtained from npcs with 500+ HP

500-999 HP: 25 Dark souls

1000-1999 HP: 50 Dark souls

2k+ HP: 100 Dark souls

Entering the Dungeon
After obtaining all the required items the Dark Enchanter will exchange them for a Dark Realm Scroll.

The Dark Realm Scroll will give you acces to the Dark Realm untill you got a Dark Angel piece drop, after the drop the scroll will be removed from your inventory and you have to repeat the above process to enter the dungeon again.

The Dark Realm
Inside the dungeon you'll find Fallen Angels, killing the Fallen Angels will give you the chance to obtain one of the following drops:

Dark Angel Set
The set offers : Infinity prayer Increases your max hp to 200 15% extra max hit damage 4.5x drop rate Lightning critical damage effect

The Other Dimension Scroll
The Other Dimension Scroll is a donator item that gives you permanent access to another area where you can find Fallen Angels, this scroll will allow you to continue killing them even after you obtain a Dark Angel piece.