Iudex Gundyr
Boss Strategy: Iudex Gundyr is your first true test. In his first phase, he's a relatively slow opponent. Dodge his halberd swings and attack his back. He wields a halberd with a sweeping attack and a lunging thrust. Patience and precise dodges are key. Look for openings after his combos to land a few hits. It is generally advisable to stay behind him as much as possible, as his attacks are primarily frontal. Be mindful of his stamina; he can be staggered if you apply consistent pressure.
In his second phase, he transforms into a grotesque Pus of Man. This phase introduces a more aggressive and unpredictable moveset. The Pus of Man has a long-reaching grab attack that can deal significant damage, and it will also spew dark, corrosive projectiles. Keep your distance, use firebombs if you have them, or stay close to his legs and attack. Staying close to his legs can be a viable strategy as some of his wider attacks may miss you, but you must be prepared to dodge his lunging attacks and the area-of-effect damage from his dark projectiles. If you are using ranged attacks, try to maintain a safe distance while peppering him with damage. If you are struggling with the close-quarters combat, consider using the environment or any available cover to create space and heal.
A common mistake is to become overly aggressive in the second phase, leading to being overwhelmed by the Pus of Man's rapid attacks and grab. It is important to remember that even in this transformed state, he has tells for his attacks. Learning these cues will allow for more effective dodges and counter-attacks. The arena itself is relatively open, offering some room to maneuver, but it's important not to get cornered. Successfully defeating Iudex Gundyr is a significant milestone, as it sifies your readiness to leave the Cemetery of Ash and begin your journey through Lothric.