When those runes spawn you have to act very fast and kill them by order BLUE>RED>BLUE and so on. If you kill red first it's a team wipe, if you act slow "you have 2-3 second" – it's also a team wipe. For each destroyed blue rune your team gets a buff similar to what clerics' "R" skill does and that will allow you to kill red runes without wipe at all (however, the buff lasts only 3 seconds). For each destroyed red rune a dangerous hound will spawn and the tank should aggro them fast. Each dog applies approximately -120 HPS debuff for those who kill it, they do have very high critic hit attacks. There will be a total of 8 runes.
Lots of mines will spawn on the left side and you have to find the real one. Mines do high damage upon destruction so it's recommended to restrain from using AoE spells for everyone but a tank (you could also buff your tank). When you find the real mine you will notice something like "9XXX" with a countdown on it (the first number must always be 9 and the rest can be any number used to pass the mini-game). 9000/9999 HP If you over DPS you can heal the mine. In case the main mine is destroyed accidentally or its HP had the wrong value when the countdown finished it's team wipe. Mine also attacks the person who gets aggro so be careful. It's recommended to deal the last 1-2k damage (prior the target HP) by one player who has no DoT and reflect damage, otherwise, it's very easy to overdamage the mine and fail the entire encounter.
Stand on purple animation until your name is called/aggro it so skull will slowly follow that person, at the same time everyone must group up while staying within very big circular lightning effect and mostly focus healing that person along with other team members. Move to top areas when lightning stops.
The orb is unstable! Give it to someone else! Within 4 seconds someone has to hug that person to grab the orb and run away into an isolated area; an entity will spawn on their head and generate shock waves around them while the rest of the team stays away from that person (except, maybe, healers, who might need to heal that person).
Tank: Keep your life more than half.
DPS: Kill it.
Healer: Heal that thing.
Number of passing orb depends on difficulty (normal 1 / Legendary 2 / hardcore 3 times, and 2nd skull follow the random player). Also at HC mode 2nd skull follow random player.
The orb starts releasing its power! That's when you need to gather again. Also, avoid touching the skulls as they do rapid damage. Check 2nd picture below as you can see 2nd skull randomly picked me to follow and i took rapid damage when touched it.
Tank stands on purple animation again after getting aggro he must pull the shade close to the torches range to make shade vulnerable to attacks. You will 5 seconds to kill the shade if the torch has been destroyed. You can always shade to other full HP torches and repeat process until he dies. After shade dies its corpse and each pillar will shoot fire bolts in all 12 cardinal directions around them. PS:
Do not worry if you have failed to kill the shade, destroyed pillars regen their HP as time goes, luring shade range of pillars is enough dont have make him hug into pillars.
A total of 4 cages will spawn randomly in outer areas along with 2 fire rain areas, which travel in a circular pattern. Also, random fire bolts will fly on the arena, a tank must auto-attack the cages to push them into where fire rain zones to purge their mana and destroy them. Each hit on cages will make you take some damage and lose mana. When cages are properly positioned, you should stay in a safe area until they are destroyed. Worth mentioning that cages also gain a little portion of their mana so at Legendary+Hardcore modes the phase takes much longer.
Tank goes to the left and pulls all phoenixes. Towers should be killed almost same time while keeping their HP close to each other, if you damage one tower too much both of the other towers will reset their HP. Upon tower description, all player's mana will be depleted and players will be left at very low HP, therefore high degen items might kill you instantly.
Dozens of apostles around a girl and a blue linked to drain her hp and you have to keep the girl alive by healing her while killing all apostles. Whenever each apostles hp reaches 50%, fire bolts scatter around the girl so don't get close so much to her, that moment blue links drain her life also will be disabled. The tank must also aggro them whenever they stop draining her HP and start attacking your team. When last apostles dies last time fire bolts will be scatter.
A total of 4 gates appear randomly at the arena, which keeps spawning "Inner Temple" mobs. Destroy all gates.