There are a lot of threads about Tyrannical being required in 9.1 to get KSM and the misconception that Tyrannical is more challenging than Fortified. At the +15 key level, the two affixes are balanced; even with the trash buffing affixes on Tyrannical weeks. It isn’t until high keys where Tyrannical scaling runs into unintended consequences. The game was designed and scaled for +15s and it is. In an infinitely scaling system, it will break no matter what at certain points given the affix. It doesn’t change the fact that for KSM, it is balanced.
Some people hate Tyrannical because it is a “damage sponge”, but I feel most hate it because they don’t understand the boss mechanics. They do okay on fortified because boss damage is more forgiving, but they make the same errors on Tyrannical and die. Many people think they understand mechanics, but they clearly don’t when I group with them.
Here is a list of boss mechanics for M+ that is commonly overlooked:
Edited: Updated some information for season 2.
Hakkar’s Blood Barrier: Using immunities and defensives decreases the shield he gets. Pop your cd right before his ability goes off.
Manastorms: Echo Finger Laser X-treme needs to pass through Millhouse, but you need to move out after the laser to not get stunned. You also don’t want to kill Millhouse before Millificent phases in, or else you won’t have the stun to stop the raining chickens.
Dealer Xy’exa: Lightning stacks and making sure you pass it to the right people, don’t give it to someone who already has a bomb.
Echelon: Adds won’t start casting until they get hit. Stack on tank and wait for them to move in. You can even decurse the person who will get jumped on so they don’t take damage if they move out in time.
HoA in general: You can control multiple Gargoyles at the same time. The trick is to tag both Gargoyles, bring them into range, and button mash your ability.
Lord Chamerlain: The statues shoot off in the direction they are facing once he targets one of them. You can visually see which statue is selected with the beam he shoots at. You can also soak more than 1 beam without taking additional damage by moving into the bosses hit box.
Ingra Maloch: You want to time Lust at 40% HP on the tree. If Ingra is at ~20% or below after burn phase - stay on the boss.
Tred’ova: Acid Expulsion follows your movements during previous ability casts. If you run across the map, the green swirlies will run across the map. Move as little as you need to.
Doctor Ickus: You can cc the purple slime to prevent the dmg reduction debuff.
Margrave Stradama: Only the tank needs to soak the big guy, no one else should be in the frontal marked by a green circle.
Kyrxis the Voracious: Group should be staggering the Living Essences. If the whole group soaks them at the same time, it will likely kill someone. You can also use an immunity on the Juggernaut Rush to prevent group wide damage, but make sure you face the boss away from the group if you are going to immune it.
Executor Tarvold: Many classes have ways to stop Castigate when it is targeted on you. Using immunities or even feign death and shadowmeld.
Grand Proctor Beryllia: When collecting orbs, you want to get 3. Alternatively, you can cycle players using immunities to everyone can get 4. Tanks only really need 1 or 2.
Venturnax: Balls shoot out in a clockwise direction from the swirlie. Tanks can stack 2 swirlies on top of each other before moving her for recharge so there are less points of origin.
Oryphrion: Use 1 minute cds at the start, but save big cds for when boss is Drained and recharging. Boss takes 100% extra damage.
SoA in general: Kyrians can activate the goliaths that will drop big anima orbs. Pick one up quickly because they will despawn. Once gathered, stay stacked on the tank. The buff will deal constant aoe damage around you and being grouped will maximize damage.
Blightbone: Turn the boss away from the group when targeted by Heaving Retch.
Surgeon Sitchflesh: You can easily one phase the boss with double Spear and no lust. Save lust and 3rd spear for last boss. If you can’t one phase the boss, point the 3rd hook back towards the platform. Boss will jump back up right before the 3rd hook goes off and will miss otherwise.
Nalthor the Rimebinder: Saving Lust and a Spear will shorten the boss fight considerably. During Comet Storm, run in a tight circle and you won’t run into anyone else. You can also use Hammers to break down his Icebound Aegis.
Xav the Unfallen: Kill whoever doesn’t have cds up during duels. Winner of the duel gets a buff.
Mordretha: Stand on the edge of the arena and you can see the Ghostly Charge much better.