Waves come in triplets, homing more aggressively on Path of Exile 2 Currency your location.
Water columns gain a freeze effect in addition to slowing.
Large, slow Water Globules spawn during the Siren's Song, further crowding the arena.

A Note on the Siren's Song

If you get caught in the golden cone for too long, the outcome isn't explicitly shown - but given the mythological reference, it likely results in an instant death or wipe mechanic. Treat it as completely avoidable at all costs.

Strategy for Beating Diamora

Success against Diamora comes down to mobility, patience, and smart positioning, and buying POE 2 Items smartly. Here's how to approach the fight depending on your build:

General Tips

Keep Moving: Many of her abilities track your last known position. Standing still invites disaster.
Plan for Obstacles: When she dives early on, kite her columns to the far edges of the room so you don't clutter your fighting space later.
Respect the Song: During Siren's Song, shift focus to dealing with adds and staying behind the cone's rotation. Don't waste resources trying to outpace it - simply follow behind it.

Ranged & Minion Builds

Best Choice for the Fight: Ranged casters and minion users will find this fight much more manageable. You can keep your distance, avoid slows, and let pets or projectiles chip away while you reposition.
Beware of Water Blasts: Don't get complacent - her fast volleys can still chunk your health if you stop moving.

Melee Builds

Most Challenging Approach: Melee characters have to brave the hazards up close. Try to lure her early dives into unused corners to leave the center relatively clear.
Time Your Damage Windows: You'll often need to wait until after Siren's Song or wave volleys to POE 2 Currency for sale commit to damage. Burst her when it's safe, then retreat.