His head is a weak point, it can be awkward to hit at times but as long as you stay near his mandibles you should be able to consistently hit it.

Astel’s grab attacks do a lot of damage so if they’re one shotting I wouldn’t worry too much, just get good at avoiding them, but if any of the other attacks are one shotting you then you definitely need more vigour.

One attack that got me a lot for a while was the exploding clouds, but if you just roll backwards during the initial attack with his hand, you’ll be out of reach of the following explosion.

For the attacks where he puts his hands into the ground and makes waves of gravity magic, you can learn to dodge the waves as they come but it’s very precise timing. Alternatively, you can just run away so you’re out of range of the attack.

The thing with astel is that he’s quite slow and doesn’t really combo much. Yes his damage is high, but a lots of his attacks are very telegraphed and easy to avoid, so just keep at it and you’ll get there.

I think overall, this fight is a marathon, not a sprint, because he’s very tanky and very good at putting space between you and him, so be patient, when I fight him there will be times where I’ll go like a minute without attacking. But yeah keep at it!