Fighting an Opponent Who Never Retreats

The battle follows a turn-based structure, alternating between your actions and Undyne’s attacks. You can use the FIGHT command to damage her, while ITEM allows you to restore health when healing supplies are available. During her turns, the combat system changes into a survival challenge where you must avoid or block incoming projectiles. Undyne has a large amount of health, so defeating her requires surviving numerous attack sequences.

Two Ways to Defend Your Soul

The central mechanic involves switching between two soul colors, each with different movement rules. Understanding both is necessary because Undyne frequently changes how you must defend yourself.

The encounter includes:

• Green soul mode, where you remain stationary and rotate a shield.
• Red soul mode, which allows free movement inside the battle box.
• Blue spear attacks that approach from different directions.
• Yellow spears that reverse direction before reaching you.
• Circular spear formations and projectiles aimed at your position.
• Healing opportunities between enemy attack sequences.

Some attacks require memorizing the order of incoming spears, while others depend on quickly identifying where it is safe to move. As the fight continues, the patterns become more demanding.

Successfully blocking one sequence does not guarantee that the next will be similar. Undyne alternates between fast directional attacks and formations that restrict your movement. In red soul mode, remaining in one location can be dangerous because several spears may converge on your position. Learning when to move and when to wait is important for conserving health.

The Conclusion of Undyne’s Last Stand

There are no separate stages or additional opponents in this standalone encounter. Your objective is to survive long enough to reduce Undyne’s health to zero. After her defeat, she begins to melt as her body can no longer contain her determination. Even then, she believes that Alphys will warn Asgore and help the remaining monsters survive. Players can restart the fight to practice its attack patterns and attempt to complete the battle with fewer mistakes.