Continuing on to the Ruin Sentinals:

Learn how to defeat the Ruin Sentinels in Dark Souls II: Scholar of the First Sin. Includes strategies, tips, and item locations.

NOTE: There is a way to skip the battle with the Ruin Sentinels. If you managed to get the Antiquated Key, you can use it to open a door past the boarded doorway in the first courtyard, right after the white knight's location. You'll traverse this area when you arrive via ship.

There's a broken pillar outside the tower which will allow you to access the heavy black door ahead. Be WARNED that the area ahead has five royal guards inside. Fighting them both at the same time is very dangerous. Ranged characters have an advantage here and are advised to pick the guards one by one. Melee fighters can run around by jumping around the ledge and crossing the pillar again to separate the enemies and engage them one at a time.

Once they are dead, go downstairs and take the ladder to the bottom floor and loot the corpse beside it to get a Soul of a Proud Knight and a Human Effigy. Better not open the iron door at the base of the stairs since you'll fall to your death. Climb back up the stairs and enter the cell to the right. There's a skeleton here containing two Radiant Lifegems. Beyond the mist you'll have to deal with the Ruin Sentinels. In the same room with the skeleton there is a summon sign where you can get the help of a phantom. Take note that you can only see this while you're human.

BOSS: Sentinels of Ruin: Alessia, Ricce, and Yahim

The fight starts on a platform with one of the sentinels; the sentinel will immediately attack with an overhead attack, so rolling or running sideways (risky due to hitbox) is ideal to avoid the attack and punish the sentinel. Fighting him requires patience, and baiting his overhead smash is the safest method to dodge and attack. Be wary of the camera and side way attacks. Then the second one will try to approach the platform; standing on the ledge will bait him into doing his jumping attack, and the player can back off to the wall behind to avoid it and punish it. It is highly suggested that players immediately capitalize on that and try to chip him before the other one attacks. After hitting the second sentinel twice, the player should jump off to avoid fighting them on the same ledge. The following part is the most challenging: fighting two at the same time.

The key to fighting two opponents, generally, is staying in front of them and forcing them to not use dangerous long ranged attacks, and to make them attack and stay in recovery frames so that the player can punish them safely without getting hit, had the other one tried to attack the player while attacking the first opponent.

Easiest Way:

• Just prior to the grey mist, there is a spirit to summon in one of the cells containing a skeleton, which makes this fight significantly easier, as he casts Greater Soul Arrow repeatedly.
• After you destroy the first one, jump down and have one person tank the second one while 2 people attack the third one.
• If you can use lightning spells/weapons/weapon enhancements, use them because they are weak to lightning.
• Or simply kite the remaining two around while the spirit chips away at them, as with enough room and warning, avoiding the sentinels attacks is straightforward.

Notes:

• Their lunging air attack leaves them quite open, however, dodging them early the moment they jump is advisable.
• Use a fast weapon with small recovery e.g dagger, short sword, long sword, scimitar...etc.
• Falling off the platform while fighting the first sentinel will cause all three of them to attack you, which will make this fight very brutal.
• Another strategy is to enchant a fast weapon with poison and get in some hits until the poison sets in. Since they have low health individually, you can play the defensive until the poison does its work.

Greatshield Strategy:

If you acquired the Tower Greatshield from Cathedral of Blue a useful strategy for anyone with at least 15 STR is to 2-hand the shield and let the summonable NPC fight the Sentinels while you tank all of their hits. Since they only deal in physical attacks as long as you manage your stamina well you should be able to go the whole fight without taking damage as the shield has 100% physical block.