Towards the end of the mission, you'll face multiple Blight Ganons. Each Blight Ganon has specific weaknesses and attack patterns. For example, Waterblight Ganon is vulnerable to fire, and Fireblight Ganon to ice. Use the appropriate Champion to counter them. Mipha is strong against Fireblight, Daruk against Waterblight, Revali against Windblight, and Urbosa against Thunderblight.
Focus on dodging their powerful attacks and depleting their Weak-Point Gauges. Many Blight Ganon attacks can be interrupted with well-timed Sheikah Slate Runes. For instance, use Cryonis against Waterblight's ice attacks or Stasis against Windblight's rapid movements. This is a series of intense boss fights, so manage your health and special attacks carefully. Defeating all Blight Ganons is the final objective.