Complete the Dark Forest on any difficulty
After a few puzzles, a couple rooms, and a lot of killing, you'll get this trophy at the end of the DLC when Dante is standing on the cliff.
Clear Path Not Lost
Complete the Dark Forest without getting lost once
The goal here is to make it to the end of the DLC by going only through the correct doors/portals. This also means you cannot backtrack, because that counts as getting lost. There are three different puzzles on your path through the forest.
Puzzle 1: Leopard
Here you always want to walk through the door that is facing east. The moon light always comes from the north. Here's a little compass to help you:
W . . E
So depending on where on the screen the light is coming from, go where east is from that view. Example: If it is coming from straight ahead, go right. If it is coming from the left, go straight ahead. Where the light comes from is different every time, so I can't lay out a path for you.
Puzzle 2: Lion
For this one you'll always want to go west. The moon is only shining in the first room though. Figure out where west is using the compass above. Once you know that, point the front of the lion in that direction so the light coming out of it's mouth is pointing at the western door. Then go through it.
In the rest of the lion rooms all you have to do is form a straight line with the light. Turn the lion so that the light is going straight across into the opposite door that it is coming from. It should look like the light is traveling right through the lion.
Puzzle 3: She Wolf
This one actually doesn't matter. You can screw up here and still get the trophy. Give it a try. If you have trouble, click the spoiler.
If you did the first two rooms correctly, you'll get this trophy while Dante is standing on the cliff at the end.