20 str, 22 dex, +23 normal club
charge attack, jump attack
EZ

Confessor, paladin build. Believe it or not I used the Stone of Guranq most effectively on this one. Astel cannot handle physical dmg. Currently 50 str, 50 faith, 31 Int, 49 Vigor. Godricks great rune active. Had trouble staying on the head for sword or dagger dmg. Tiche did her job well as soon as I started running in toward the boss. Remember to dodge to the side for long range attacks.

was rather easy for me:
60str,heavy greatsword +25 with Lions Claw AoW. , bullhorn chest and pants,rest crucible knight. mixed physiq: str + guard break.

Flame GMS + Golden Vow buffed, run up to its head and just go apeshit with Lions Claw until guard break, riposte and he is already almost dead.

Lions Claw has hyper armor plus that frontflip which will always hit the head

Only after Tiche FINALLY STARTED ATTACKING did the boss actually start melting, 7 attempts, and no Spirit Ashes felt like taking aggro from the boss, not even Greatshield guys. But the moment Tiche finally decided "oh yeah, I'm in a boss fight" the last 40% of Astel's Health plummeted.

Spend your runes before fighting this boss, if your spirit summons does what mine did here you'll be fighting Astel solo while they slowly walk the perimeter of the boss arena.

Enter the arena, see Astel, remember how I hated the fight with the first Astel (killed him on 5th try), **** this guy, **** this place. Didn't bother and left him.

Might come back totally over-leveled just to spank him easily and laugh, because **** him

After half a dozen ulcerated tree spirits, nine erdtree avatars some of them putrid, two Mohgs, two Astels, two Margits and one Morgott, a golden shade and then the real deal and f**k knows how many burial watchdogs, I think the unique in "bosses are unique and challenging enemies" is redundant at this point.

I had an issue with this boss earlier on. I summoned the mimic but all it did was walk around the perimeter of the boss area while astel was fully focused on me, that turned out exactly the way you'd expect. I thought the issue was the mimic so I tried dung, he was very good for this fight in my first playthrough but this time he did exactly the same thing as the mimic just walking slowly around the boss room and doing sweet f**k all else. Radahn's rain was doing good damage to its head but I think I got to double figures with how many times it killed me.

How i cheesed this guy, use latenna, put her near entrance door. use greatshield and consumables (kukri and poison dart or pots if you want), rotten breath, shabiri woe and magic defense talisman, armor heavy on magic defense. shield with high magic defense. Seriously, his attacks are easy to dodge as long as you keep proper distance. Lock on his head for poison dart and kukri. I poison him first, then rot him, and finish it up with kukris, the blood loss damage on him is insane. I didn't even need to use any flask to restor HP, only to restore FP after rotten breath. Only use rotten breath when he's using the 3-tier gravity slam since his recovery time is long on that. Don't get greedy attacking and you're fine.

This boss is a shining example of how **** the late game design becomes in this game. It's mostly a carbon copy of the earlier Astel because I guess From wanted to go ahead and get the game over with, and their idea of making it unique was to include one of the single most ******* attacks in the entire game: the clone teleport grab.
The boss can use this attack at any point once you've knocked down about 50% damage (and uses the regular grab once you've hit 20%), and you'll only know the attack is coming once you see multiple portals above you. The first time the boss uses this attack, you can run to the center of the area and likely avoid it, however the second time you literally cannot get away from it. Run to the middle? All of the clones converge to that spot. Roll through? Nope, can't roll through grab attacks. Run through and get behind? The ridiculous hitbox will cause you to still get sucked in. Maybe jump? Maybe jump off a bridge instead. The only way to avoid the second clone grab is to kill the bastard if you have the chance. I've gotten the health down to a smidge, then boom the Naruto crap kills me.
I've played this game for entirely too many hours, and when I first bought the game I wanted to go through and defeat every single boss. This one is NOT worth it.