XCOM 2

The Berserker Ruler, AKA Berserker Queen, is one of three alien rulers encountered in the Alien Hunters DLC. It is arguably the second hardest Alien Ruler to defeat.

It will be the second alien ruler you encounter if you´ve enabled the mission "Alien Nest" at the beginning of your playthrough. If you have not enabled the mission, the alien ruler encounter order will be random.

Like all other alien rulers, the Berserker Queen performs one action after every action made by XCOM during a special Ruler Reaction phase. Some abilities do not trigger Ruler Reaction, like Lightning Hands or Bladestorm.

At some point, when enough damage has been dealt to it, it will open a portal and attempt to escape (if you kill it as it attempts to escape, you will get the achievement "Not throwing away my shot" if you don´t have it already). If it escapes succesfully you will randomly encounter it in a future mission, but it's health will be the same as last time, it does not regenerate.

It is unlikely you´ll be able to defeat it during your first encounter, however, if you manage to do it, you will get the achievement "Regicide" if you don´t have it already.

Here is the strategy for fighting the Berserker Queen:

She has three attacks:
1. Devastating Blow: melee attack with a chance to disorient.
2. Quake: AoE attack that deals damage and has a chance to disorient, stun or render unconscious.
3. Faithbraker: scream that triggers a will check in all squadmates, if failed, the unit will panic.

She also destroys most cover by running through it, or when she does a melee attack.

General tips:
-Take off its armor ASAP.
-Hit it with effects that do damage over time, like burning or poison. It will take damage in every reaction phase.
-You can counter Ruler Reaction with flashbangs, frost bombs or attacks which can stun.
-Do not bother taking cover. It won´t really help you at all.
-Try to fight it when it's alone. If possible kill all other nearby enemies first.
-Do not group your squad too close together, to prevent multiple of them getting hit with the AoE attack.
-Move as little as possible. Try to use all your actions to attack.
-Use free actions as much as you can.
-You can use the button to end your turn manually and get back actions from soldiers who already used their actions.
-Psi Op's Stasis ability will lock the Berserker Queen down for an entire turn.
-If War of the Chosen is installed, the ability Dual Strike, available when two soldiers have a level 3 bond, can be extremely useful.