You come across your first boss pretty quickly in Scarlet Nexus, and it's quite difficult as you're no doubt still getting used to the battle system. Gunkin Perry is the name of the first Major Other you will fight, and it quickly eases you into one of the vital mechanics of the fight system, that you can use massive objects of the arena as weapons.
To beat Gunkin Perry, keep your distance and dodge all of its projectile attacks. Patience is key. You need to wait until Gunkin jumps into the air coming right at you. Move out of the way, and look at the massive giant cylinders above the battlefield. Hold LT the second the boss impacts the ground, and you'll use your psychokinesis to slam it into the boss, dealing massive damage and stunning it.
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Now is the time to press the attack. Use your Rush Follow-Up Attack (RT and then as the object lands X, Square, or Left Click). This will allow you to get in close quarters quickly. The second you do so, activate SAS: Pyrokinesis by pressing RB and B, R1 and Circle, X + 1, as Gunkin Perry is weak to fire.
Once the Major Other gets back up, repeat this process until dead and a cutscene plays. If you have played the demo, you will have noticed you only have one person in your party instead of four.
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