Concentration | Fury
Concentration is the burst spec for the Sentinel. Like its cousin, the Focus Guardian, the rotation is very unforgiving of mistakes. If you mix up an ability, it stays that way forever (unless you basic attack a bunch to reset all the cool downs). The order of the abilities seems to line up the cool downs exactly, so hitting zealous leap a GCD sooner means it's stuck in that GCD block indefinably. The class seems to have a huge upper limit as far as Single Target dps goes.
Gearing up for Concentration
Below are the gear selections, legendary implants, tactical and skill point choices I recommend for this class.
Sentinels require prefight prework to start at their maximum potential. They require at least two tacticals, one for prefight and one for the actual fight, making them have a somewhat higher barrier to entry to perform well. Be sure to get a feel for how your raid team is doing its pulls to react to when you need to prep. The worst thing that can happen is to have the wrong tactical in from someone accidentally pulling the boss or not giving a countdown/ready check. Get to know your group and if you find they are face pulling everything, play it safe and keep your primary tactical in.
Step 1: Build 30 stacks of Centering. Activate your out of combat health regen and build 30 stacks of centering.
Step 2: Swap out your tactical to hidden power and activate force camo. This will begin to build your focus, be sure to swap back to cauterized coronary (you can do this immediately after hitting force camo) to be sure you are ready for pull. Note that you can put your tacticals on your Quick bars for ease of swapping.
With concentration, we need to start by leaping in to proc our first focused burst.
This ability is a staple of the sentinel, but it behaves differently in each of the three disciplines. For the Concentration Sentinel, Zen provides us additional focus building necessary to keep executing our high damage abilities. Without Zen, concentration doesn't work. Zen also buffs Focused Burst, providing the same "Koan" buff that Force Exhaustion does. Between Zen and Force Exhaustion, every focused burst we use will be buffed.
Concentration has four ability blocks we are going to have to learn to perform well. We use two modified blocks in our opener to set up our two rotational blocks. It is a bit more to memorize, so I recommend parsing against a dummy target until you feel you have each part down before trying more challenging content.
Once you are through the opener, continue with the following rotational blocks and continue to repeat them. You'll find boss fights where you will need to repeat your opener often. Gharj in Eternity Vault is a great example of a boss you will need to repeat your opener. There is enough downtime in between him knocking platforms out that you can set back up for your opener every time he comes back. It's a great fight to practice that opener and your rotation.
The key behind this block is to regenerate your stacks of centering back to 30 to activate Zen.
This block is the one we use Zen for and is the higher damaging block. When our adrenal comes back off of cool down, we want to save it for the Zen Block.
Be sure to always hit Zen immediately after a focused burst. We will be running low on focus, but more importantly we need the Koan buff for our next focused burst as Force Exhaustion will be on cool down from the previous block. Do not hit Zen before or with Focused burst in this block, as we already have the Koan Buff from using Force Exhaustion, and it will be wasted.
Once your target hits sub 30% HP, start substituting in Dispatch in place of the "slashes" for more damage.
So, after parsing a great deal with concentration, I have found what I believe to be a comfortable way to insert inspiration into my sequences. When Valorous call comes off cool down, here's what I do. I save it and wait until I get back to the "Zen" Block. I hit Inspiration Before I hit the Focus Burst in that block. I then immediately hit Valorous Call + Zen, and then continue with Concentrated Slice and the rest of the Zen Block. Keep in mind that Valorous Call and Zen are off the GCD, so there shouldn't be any delay in your Sequence.
Quick Reference Guide
The Sentinel is a bit unique as it has 2 "Raid Buffs" Inspiration to the left is the traditional raid buff giving 10% damage for 10". It requires 30 stacks of centering, making it a choice between Zen or Inspiration off the break.
This unique raid buff is on a 30-second cool down and requires selection from the skill tree. Transcendence gives the raid an 80% speed increase, 10% damage reduction and cleanses movement impairing effects. I use this on cool down even if I am not moving for most fights. Save for movement in movement heavy fights.
Concentration's Defensive Abilities
Last for 12", this ability gives us a 50% chance to dodge Melee/Ranged damage and a 25% Damage reduction to Force/Tech attacks. It is on a 3-minute cooldown. It's a strong defensive, but its long cooldown means you will most likely only get to use it once in a fight. I save it for emergencies, mostly.
This is our self cleanse, threat drop and a 50% DR all wrapped up into one ability. Note that dealing damage ends the effects of Force Camo Early.
This is a staple of the Sentinel. Rebuke reduces the damage you take by 20%, so it fits in as a defensive cool down. However, it also reflects damage back to the attacker. A common strategy for sentinels is to "stand in stupid" as long as the healers can handle it. Say we stand in a spit puddle on Writhing Horror, for instance. Pop rebuke and reflect that damage back to the boss. As we take damage, we extend the duration of rebuke up to 30". With our selections from the skill tree, rebuke becomes a very short fused cool down. Matching its use (assuming we can continuously take a light amount of damage consistently in a fight) with our choice for a permanent 30% AoE DR and the concentration sentinel quickly becomes able to soak an impressive amount of damage while reflecting a notable amount back at the boss. It's a good practice to get into using rebuke not just on cooldown, but when you know you can take light - moderate amounts of damage without stressing the fight.
A short cool down (35") defensive or movement ability. Blade Blitz can take some practice to know where you are going to end up. You can use this to completely ignore (100% defense chance) high hitting damage types (doom on Dread Guards). It has a lot of utility once you master it.
This is our other choice (if not taking blade blitz). A 99% Damage Reduction for 6" has the potential to soak an impressive amount of damage. Keep in mind that a 99% DR still lets 1% through, so a mechanic like Doom listed above that hits for 136 million damage will kill you through, guarded by the Force.
Legendary Implants and Tactical(s)
The three Different Sentinel Specs each need a different Legendary implant and tactical. You will see some cross over between them and some cross over between Sentinel's and Guardians. The tactical and one of the implants here are shared with the Focus Guardian.