A full guide to the new map, Dark Omens - Dark Tongue challenges.
Dark Tongue #1
I'll keep this as simple as possible. I didn't find out any of it but I was really annoyed I couldn't find any guide to it in the guides section so I'm throwing it up. I might however be the first one to clear Dark Tongues 3. Since it's really silly.
There are 10 runes on the map. Activate all of them and clear the map to get Dark Tongue 1 completed.
1-2 are in the first area you drop into, before you encounter the Beastman Ambush
3-5 are in the area right after the Ambush, before the next drop-off
6-7 are after the next drop-off, after you see the big vortex
8 is in the area where you have to cross a chasm over a toppled tree
9 is in the area where you have to jump over a small gap to continue to the next area. The rune is on the bottom of the gap
10 is in the big ruins area, somewhere on the right side of the zone, if you're facing forward from where you came in
Please use the image to help you out.
Dark Tongue #2
This part requires you to activate the runes in a specific order and backtrack a little bit after the last one.
1. Run through the map like normal, activating the 1st, 3rd, 5th, 6th, 8th Mysterious Rune. Once you get the 8th rune (The rune before you have to cross the burnt tree over the chasm) you should hear a ding.
2. From here backtrack to the second tome. There is a bolder at the back of this cave. Go up to it and push it out of the way.
3. On the left side of the base, in the water next to an impaled corpse is a key. Grab it.
(The key seems to move around the cave like other key spawns so you will just have to find it. It seems to always be around the edges of the cave.)
4. Go to the end of the level. Near the entrance to the crater is a locked chest. Use the key to open it up and grab the unique painting inside.
Dark Tongue #3
This part is really, really silly. People were looking everywhere for hidden messages...
All it seems that you have to do is. (I haven't tested it a 100%) Loot the chest in the lair of Dark Tongue 2 and keep the loot until you clear the level.
Take the key from the lair and go to the end of the level, before jumping down to the meteor, unlock the chest, make sure to loot everything and don't use it until you've cleared the level.