Moonlight Butterfly is one of many optional bosses in Dark Souls, found as you explore Darkroot Garden.
Moonlight Butterfly boss strategy
In Darkroot Garden, the Moonlight Butterfly is certainly not a huge threat to you, even if you might be weak to some of its attacks. It can be a tricky fight for those that have not brought along a ranged weapon however ,as Moonlight Butterfly spends a lot of her time in the sky. This enemy also spams a lot of Magic attacks, so be sure to equip your best magical defense shield before going in.
Right, on entering, you'll realise that tyou might not have as many options as you thought you did. With the arena being one big straight line, it also means that there is nowhere for you to hide, which can be a problem if you're in the way of the Moonlight Butterfly's most powerful attack- a straight up laserbeam.
You will be able to tell when the butterfly is doing the beam attack, as it has a fairly large windup, so you definitely won't miss it. If you're stuck in it, try to dodge or block as much of the magical damage as you can in order to ensure that you see the rest of this fight through.
Next, you might find that this fight will be a bit harder for melee characters,just because you'll find yourself waiting a long time before the Moonlight Butterfly decides to land and sit still and take some damage- but beware, as it can also charge up another attack whilst you're wailing on it. If it flies off, we recommend you use sorcery, pyromancy or a bow, as they can all deal some pretty decent damage.
Right, now that the boss is back up in the air, it's going to attack with one of two options- a homing magical blast, or "darts" that spurt out in every direction. For the homing attack, we would recommend that you try to roll out of the way, but in the case of the "dart" attack, you're going to want to just hold your shield up to eat most of the damage.
Another thing to keep in mind is the arena- if you are playing a light build you might need to ensure that you know the invincibility frames of your dodge roll to to the side of the homing missile attack or the darts, which although difficult, should not be impossible to dodge if you position yourself correctly to the edge as it charges the attack up, which you should definitely be doing if you don't want to tank those hits as a high-poise build.
If you're looking for more help, our Dark Souls walkthrough and guide can help with all other areas of the game, including the dreaded Taurus Demon, Capra Demon, Ornstein and Smough bosses. Meanwhile, we have explainers on how to access DLC Artorias of the Abyss, the best gift and best class in Dark Souls, Dark Souls' best weapons, Dark Souls Covenants, Dark Souls Estus Flasks locations, Dark Souls Titanite Slab locations and NPC quests including Lautrec of Carim.
There's not a whole lot to the Moonlight Butterfly, nor is it too difficult, just ensure that you've kept your ranged options open and this fight shouldn't take too long to beat at all. Even if you're having trouble with the limited melee attack window, the majority of the fight is a test of patience over everything else.
Watchtower Basement Key location
Again for melee users, just two-hand the weapon and it'll be over very very quickly. Then, head to the pillar at the end of the fight to get a Divine Ember and Watchtower Basement key. Then, head back up towards the bonfire.