how to unlock melisandre?

[RileyX]

how can I unlock melisandre?

[76561199229242662]

First learn how to reliably survive first map.
Then unlock Compass and/or Map (just pick up gold and stuff).
Finally in the beginning of a game press Esc and look at the map. Find "?" sign - that's where Melisandre is. Go there. Compass in the bottom right corner of the game screen will help. It's a long way, be persistent. Run around Melisandre until she teleports away and you get "Melisandre saved" prompt or something.

[M4RK0]

It takes roughly 10 minutes to get to her if you start moving to her direction from start. Try to get there before 15 minutes. Kill the stationary enemies around her and she's freed. You don't have to keep playing that run after you save her.