The Architect of Ruin is the final boss, located at the Heart of the Desolation. This multi-phase encounter tests all your skills and Relic Abilities. Phases:

Phase 1 (Wind & Earth): Attacks with rapid wind projectiles, sweeping gusts, and ground-shaking slams. Use Gust Dash to dodge, Ground Pound to stun.
Phase 2 (Water & Light): Incorporates powerful water blasts, whirlpools, laser grids, and blinding flashes. Use Hydro-Blast for damage, Light Barrier for defense/deflection.
Phase 3 (All Elements & Core Exposure): Combines all previous attacks, often in rapid succession. After a devastating, full-elemental attack, its 'Heart of Desolation' core becomes briefly vulnerable.

Weakness: Its core, vulnerable after specific elemental attacks. Strategy: This fight is a test of endurance and adaptability. Constantly switch between Relic Abilities to counter its attacks. Use Gust Dash for evasion, Ground Pound for stuns, Hydro-Blast for ranged damage, and Light Barrier for defense and deflecting projectiles. During Phase 3, identify the brief windows after its most powerful attacks when its core is exposed. Unleash all your strongest attacks during these moments. Manage your Momentum Gauge carefully. Rewards: Game Completion, unique 'Architect' Waverider Skin.

Architect of Ruin (Final Boss) - Sword of the Sea screenshot — Architect of Ruin (Final Boss)

How to Beat Architect of Ruin