Comments posted to our Dark Souls 3 Wiki
Fought him yesterday and for some reason a player summon turned up before the fight.
Is there a reason for this? A random player being summoned or did I blackout and summoned someone !?
I had this happen for the darkeater boss, i was changing my armor around and someone just showed up. Glad though he helped me take care of that miserable dragon.
It was the boss invasion glitch
OH, you mean that glitch when they actually can attack you, too(?)

Well, then I am also KINDA glad he helped me.
Though I am a bit disappointed I couldn't fight him alone.
If it was a white phantom, he was probably wearing the untrue white ring, as it makes dark spirits look like white phantoms. Luckily, you found one with a conscience!
Sorcery Strategy

Taking on Slave Knight Gael with purely sorceries is a tough battle but can be done if you keep your distance. Alot of his attacks will outright miss if you run away from him and remember which attacks where you have to roll to the side instead.

Being able to defeat Gael also requires FP management and avoiding most of his attacks as you need alot of Ashen estus for this fight. Running out of FP during the fight is possible and I have died 1-2 hits away just because I didn't have enough FP to finish Gael off. I suggest at least 7 Ashen Estus. Simple infused weapons could be helpful but it takes way too long just to recover enough FP for one CSS casting in my opinion.

With a +10 Court Sorcerer's staff, the Scholar's Candlestick, Crown of Dusk, Bellowing Dragoncrest Ring, Young Dragon Ring, and Sage Ring +2 at 60 INT and 28 Attunement, you'll have 4 Crystal Soul Spear (CSS) casts and 2 Heavy Great Soul Arrows (HGSA) before running out of FP and Ashen Estus.

First Phase

When you first enter the arena, Gael will be very far away but rushing to your position. You can get two CSS castings in with the Sage Ring +2 before having to dodge his first attack.

-Critical Strike
Roll to the right, and then punish immediately with CSS.

-Plunging Attack
Run away and roll back before he plunges down with his sword and then punish with CSS.

Run away and roll back if you're too close right before he initiates each attack. Punish after his third attack.

-Sword Attack
Run away and roll to the right before each attack. Punish right after his 2nd attack.

2nd Phase

Phase two will occur roughly after taking 1/3 of his HP. I suggest recovering your FP to max before the your last hit that will initiate the 2nd phase. This way you can get 2, possibly 3 free CSSs and stagger Gael if he attacks.

-Repeating Crossbow WA
Stay at medium distance and circle rightwards Gael. Punish after he uses it twice in a row.

-Way of the White Corona
Circling Gael rightwards and running away will avoid the attack when the disks come boomeranging back toward him. Gael usually uses his repeating Crossbow right after so punish right after his crossbow animation ends and you're safely out of range of the disks.

-Coat Rush
If Gael rushes toward you and try to attack you up close, rolling to the right is much better than rolling back as his coat will extend the range of his sword attack.

-Soul Explosion (1/3 HP Bar left)
Get as far away as possible but in range of CSS. You can get two castings of Crystal Soul Spear with the Sage Ring +2 before having to dodge his souls. It's free damage so try to restore your FP right before you take out 1/3 of his HP.

Phase 3
Stay as far away as you can and roll right. He has two attack sequences he'll primarily use as well as the previous attacks he has.

-One where he's charged with souls and does 3 attacks in a row. You can punish Gael with a CSS if you're far away enough to avoid his tracking souls after his 3rd attack.

-The other attack sequence, Gael does multiple flips in the air. Run away and roll. Punish with CSS after his 2nd attack.

I suggest only attacking after he uses his two-attack sequence where he spins in the air. It's the safest option by far compared to his soul-charging sword attack.
Anyone else notice that a summon sign appears where he teleports? He literally leaves our world and summons himself back in with a white sign to attack you.
I know right?
**** fight
Prob worst boss of dlc
Get better b8, m8
bleed does work on him but you have to hit him about 8-12 times within 20 sec as the build up drops fast on him apparently.
I'm pretty sure that they silently patched the toxic+poison mist strat. He now moves out of the range of both but is still unable to get to you. I guess you can still use the corner if you want a bit of a breather or something.
Gael seems to use the corner as well. I guess he and Friede would deal with good ol' Dorhy and her... (yo!)
his toxic defense is now so strong i infected myself throwing***** at him
Did anybody else just have him stop moving altogether? Like he just stood there and let me attack?
Does this when he has two ongoing effects happening at once. It's a fun exploit when you use toxic mist with snap freeze. Get him toxic and thenspam snap freeze and eventually he should stop moving for 30 seconds or so.
I just finished off Gael again on one of my characters who was currently hollow. I often don't wear a headpiece with this character so it was easy enough to tell if he was beef jerky or not, and while wandering around looking at the scenery after the fight I noticed my character was no longer hollow.

I didn't receive the "Hollowing Reversed" message or anything like that and definitely didn't do it myself as I had no purging stones remaining and needed to visit the monument or Velka shrine to reverse it.

Can anyone who is playing a character who hasn't beaten Gael yet do the fight while hollowed to test if defeating him reverses hollowing?
I did, still hollowed though.
While the fight is cool, I was really disappointed in its difficulty. I'm not particularly good at Dark Souls at all, and yet I beat Gael on my second attempt with my shield and board quality build knight.

I liked the DLC a lot, but I was expecting a MUCH tougher time with the very last boss in the Souls series.
that is the build that currently is best. greatshield?
Complaining about difficulty on a scrub quality Build with Shield is pretty hilarious. Just saying.
Try NG+2 at least to collect all the boss soul weapons (nameless King) and we'll talk. I thought he was a chump on the first playthrough and NG+1... definitely the hardest boss in dark souls 3................... s/o...nothing beats amygdala in the cursed chalice dungeon though
Can be headshot by a bow or a crossbow and critticaly strike during this animation idk if i can edit this page and am to lazy to do so but i dont see it written on here so ima leave a comment
during what animation?
Guss stagger animation... From have patched all RPG elements from this boss, except good ol' pyro/cleric bugzz, now they'd go and nurf crossbows and bugz. And we get yet another Niohborne crap where all that is left is dodge and press X (to win)
while he is staggered from the headshot when i hit him my white phantom reposted
guss stagger animation?