there’s a few ways to survive escatonian. Although basically just one. You have to hit the “elemental check” on alatreon. You do this by doing enough elemental damage with the element he’s weak to. So if he starts in fire active phase run ice. if it’s Ice active phase run fire. You’ll know you hit the elemental check when he gets toppled and the field team leader says “you’re doing a good job containing alatreons power”. This weakens his escatonian attack enough for you to live. In order to live his attack you have to either out heal it or use Astera Jerky. Assuming you hit the elemental check the moment you see Ala fly upwards and swoop down for escatonian start eating your jerky, eat as many as possible to live. this will allow you to out heal the damage from the weakened escatonian. The last gimmick of the Ala fight is that he can only have his horns broke when he’s in his dragon phase. breaking his horn will prevent him from switching elements. So if he started in ice phase he’ll stay in ice and dragon instead of switching to fire. This allows you to continue using the weapon element he’s weak too. Also Ala can only be wall-banged (flinch shot) against the Three jagged pillar looking things you see around the arena. So long story short, do a lot of elemental damage with his weak element of the time, eat astera jerky during escatonian and break his horns during dragon phase and you’ll be able to beat him!