Alright, Realization is the first time you'll see Winged Girgashiy and also the first time you fight a Girgashiy with Shield of Trust. It looks like he'll start off completely immune to all your attacks so don't bother trying to fight him. Wait until he does Mineral Hail, you'll be able to tell when he crouches and jumps into the sky, use Shield of Trust then. You'll get a cutscene and you can begin dealing damage to him.

From this point forward, summon a pet and set it to attack the Girgashiy, remember you can command your pet to attack something with a ctrl+shift click. You yourself can start going for him as well, just watch his staff attack. The best place you can be to avoid it is behind him, if you don't have time to do so, strafe over to his right side or your left. The reason is that Girgashiy's 180 degree damage radius for staff is slightly angled more to his left side.

Keep using Shield of Trust when he uses Mineral Hail, you won't get any damage reduction yet since the skill is rNovice but it'll stun him so you can get a few extra attacks on him. Mineral Hail deals 25% of your max health on hit, watch your health.

As with the wingless version, he'll use Holy Contagion, bring lots of potions or have Life Drain to keep yourself alive. Demi can also work. Beware however that it's percentage health damage so if you want to trans for extra damage, you'll also be taking more damage from Contagion and Mineral Hail. Contagion lasts for 5 seconds and deals 5% of your max health per second, keep this in mind.

Between 60-40% and 25-5% of his health, Girgashiy will start using Holy Confinement. He'll stand and jab his staff into the ground, he'll also be untargetable during this animation. You'll be trapped in a crystal, unable to do anything for 4 seconds and take 1% of your max health per second and 4% of your max health as wounds per second. You can break free before that by having something kill the crystal. Call your pet back to attack it or use on-summon damage pets. Be aware that if you don't break out quickly, you're susceptible to all of Girgashiy's other attacks.

Between 50-5%, Girgashiy will use Fanticism. He'll teleport to you and grab you, and smash you with his staff. This deals massive damage and you definitely do not want to get hit by it. Since you won't be able to do anything while you're grabbed, you need to rely on your pet to save you. To break his grab, you need to hit him 3 times, your pet should have plenty of time to do so. If you successfully break free, Girgashiy will receive a debuff that reduces movement speed by 30% and strength by 40%. If you let him do it, you'll be sent far back with a large amount of wounds plus he gets buffed the same amount. Keep in mind that in that 5 second period where you're grabbed, you can also take damage from Contagion. Keep your health up and your pets summoned.

Now when he gets to 25-5% of his max health, he'll start to use Soul Absorption. He'll stab himself with his staff and spawn of soul of you that will run toward him. When you see his animation start, get away, get far away. He'll stop when he takes enough damage so your pet, Altam, and Avelin are your only salvation here. If you let your soul get too close to him, he'll heal 2% of his max health and instantly kill you. Fortunately for you, attacks stun the soul and make it stop moving. Only players can attack it so don't try using your pet to anchor it. It is also possible to break it by lance charging once your soul has been spawned, but you'll need to be far enough away to give yourself time for it. If you lance charge and manage to burst all the required damage down before souls spawn, you'll glitch it and spawn a soul that will walk to Girgashiy's position when he started it and it'll stand there. You can use this to train skills, but if he uses Absorption again and he'll close enough to the glitched soul, you'll instantly die. I wouldn't recommend it.

With this, you should be able to beat it. Good luck.