basically, after you kill the first 5 bosses, someone hires phantom to track the player down and kill them. then, every few bosses, he’ll appear as a quick time event after the boss fight where he attacks you. you must dodge him and attack him back a few times before he retreats. eventually, after the 3rd time he does that, you decide to follow him and see what he’s up to. you follow him to a clearing, where he’s just taking a rest. because he’s unarmed, he doesn’t attack you, although he 100% wants to. you interrogate him for a while until an inconvenient bird starts attacking you. this gives him time to grab his stuff and retreat. you do a quick chase scene across the forest before you end up in a grassy field. he is standing right in the middle, waiting for you. the fight begins.
Phantom is faster than the default run speed, although you can outrun him with upgrades. He will attack quickly with his sword. The fight is mostly about parrying. At half hp, he pulls out his gun, and uses it every few attacks. You must parry the shots while getting closer to attack him. At a quarter of his health, his move speed increases by a lot. There is no running now, as he can outrun you even with upgrades to your speed. At 0.1 hp, a quick time event plays where you swing your weapon into his face, breaking his goggles and making him drop his sword. In a fit of blind rage, he attacks you with his robot arm. Failing once results in death. If you successfully block his attacks 3 times, your character smashes their weapon into their head…
You leave the scene, going about your journey as normal. But little do you know, he has one last surprise for you… a jar of corrupt substance, hidden in his pocket. This won’t be the last you see of him.