Palworld

Saya and Selene can be found at -602, 214 in the Moonflower Tower and they have 261,000 health.

I was able to beat them with a level 50 character and about 150 rounds of assault rifle and 20-40 shotgun shells with a pump action shotgun. I’m overestimating my usage I believe, but it wasn’t that bad.
The Armor I wore was heat resistant pelt armor.. I forgot to change it but it doesn’t matter if your world settings are right since you’ll barely take any damage.

I only had 3 points put into my attack stat so if you have more this should be even easier for you!
As stated earlier, make sure your world settings are favorable to your damage output and health, specifically the following:
Damage from pals multiplier 0.1
Damage to pals multiplier 5
Pal auto health regeneration rate 5
Damage from player multiplier 5
Damage to player multiplier 0.1
Player stamina reduction rate 0.1
Player auto health regeneration rate 5

Defeating this boss unlocks the ability to challenge “hard” tower bosses which is required for the Champion of Palpagos Islands Achievement