Ancestor

"You still foolishly consider yourself an entity separate from the whole, but I know better. And I. Will. Show you."

- The Ancestor

The Ancestor is part of the final boss of the Darkest Dungeon. Whether he is an illusion brought on by the madness of the dungeon or he has truly betrayed his humanity for other-worldly powers, he has come to put an end to your party.

Behavior
The Ancestor has only 5 health points, but is immune to all forms of damage during this phase. He will first summon 3 Perfect Reflections which you can deal damage to. After dealing a deathblow to any one of the Perfect Reflections, the Ancestor will summon more reflections to fill in the missing positions at the start of the next round.

Sometimes the Ancestor will summon Imperfect Reflections, and when these are killed the Ancestor will take 1 damage. Be sure to kill at least one reflection every round, because if all ranks are full on the Ancestor's turn he will use Time Heals All and heal every reflection. Once 5 Imperfect Reflections have been felled to wipe out the Ancestor's health, he will move on to his second form.

To explain in detail how this phase of the Ancestor acts, here are the exact probabilities/odds:
 * He will only use Perfect Replication ONCE; afterwards, it will be either of the other two options;
 * Imperfect Reproduction starts with a 2.0 chance of being used by the Ancestor, increasing by 6.0 each round that goes by. That means, the longer the fight goes on, the more likely he is to use this skill.
 * Sporadic Reproduction has a fixed 50.0 chance of being used by the Ancestor, disregarding how many rounds have already passed.
 * Time Heals All has a mere 5.0 chance; this skill will most probably only be used if all Reflections are alive, and he cannot use either one of his other skills.

Strategy

 * For the first form, killing an Imperfect Reflection will always deal 1 damage to the Ancestor. The Ancestor himself does not attack, only summons, so you'll be dealing with at most 3 attacks. If you're able to kill the Reflections quickly, your party won't suffer damage, following similar strategies when dealing with The Collector.
 * Note although the Ancestor's resistances to DoT skills is extremely high and under normal circumstances he can't be Blighted nor Bleeded, with the right Trinket and skill combination, you can pull it off.
 * Namely, this is possible with two Grave Robber using Poison Darts and one of them having the Blighting Satchel+Blight Amulet combination. Although the initial chance won't suffice to cause Blight to the Ancestor, stacking the Blight Resistance Debuff will let you achieve it realistically after 2 rounds.

Abilities
* 50:50 chance to summon either.

** Twice as likely to summon the Perfect Reflections

Second Form
"The flesh is fluid, it could be changed, reshaped, remade!"

- The Ancestor

Behavior
The Ancestor's size grows bigger and he summons 3 Absolute Nothingness. These summons function much like the Shattered Pew of the Prophet fight in that they simply are there to set the Ancestor's position to the back. The Absolute Nothingness have extremely high resistances and dodge, which makes them impossible to hit.

When killed, he will cocoon himself within a Gestating Heart.

Strategy

 * Although you're unable to deal damage (or hit) Absolute Nothingness, they can still be attacked. This allows your party to self-buff or adjust position in order to prepare for the second round.
 * In this phase, the Ancestor's resistances plummet down as depicted in the Stats Table. Therefore, in this phase you can apply DoTs to him with very high reliability and even Stun him, which, considering the Resistance chance, can also be done pretty safely and thereby prevents him from acting.
 * All in all, this part of the fight is pretty straightforward and easy, giving you ample time to recover from the last part, should you have the necessity to do so. Stunning him while healing HP/Stress can be a good idea, since the next part is set on a timer and will advance to the Heart of Darkness after 3 turns.

Trivia

 * Even if the ancestor in his first form is immune to all attacks in game he is shown to have 80% protection. This is, because protection was programmed to cap at 80%. Ancestor in reality is protected by something else.
 * Some of his quotes for example: "Remind yourself that overconfidence is a slow and insidious killer" or "How quickly the tide turns" became internet memes.