Xylia
Terrarian
This happened way back when hard mode was first introduced, we just beat the Wall of Flesh and returned to the surface... game was like "Hope you like this Hard Mode Bloody Full Moon"
Assuming you stay in a pure forest, the only three things to worry about are possessed armors, werewolves, and the harder demon eyes. Oh, and I suppose ghosts too.
So you just build a rope straight up and put a small platform in the air and only the eyes can touch you (the ghosts are limited to floating 3 blocks above the surface). Use a Yo-Yo, ranged, or magic weapon to kill the stuff, hey maybe a moon charm will drop. Just don't let the flying eyes knock you into the mosh pit.