The cosmic entity tends to swim away frequently which is crucial to understand for the fight timing. When it starts glowing bright gold that's your cue it's about to retreat and launch either the elden stars attack or those sword beam combos, so be ready to sprint diagonally. The most reliable strategy is staying mid-range, about 20-30 feet away, since this baits out the more predictable attacks like the fire breath which has a 3-second telegraph when its head rises.

Watch for the golden rings during concept of orders, you'll see them forming at 70% and 30% hp thresholds specifically - jump these instead of rolling since the timing window is more forgiving. Getting behind it is absolutely critical when you see the throat glow for the breath attack, and if you're having trouble closing distance, black flame weapons will help since they deal percentage-based damage even at range. The elden stars move is particularly nasty around 50% hp but you can avoid it entirely by sprinting in a tight circle pattern, just make sure to save enough stamina for the follow-up sword slam that always comes after.

For positioning specifics, stick to the middle sections of its left or right side during regular attacks, this gives you the best view of its telegraphs while staying close enough to punish recovery frames. And whenever you see that golden particle effect building up around its body, that's your 2-second warning to start moving since a retreat is coming - use those moments to close distance or heal depending on your resources.