Stay close as much as you can, they wont heal if you are close

You need to be in his face the entire time, dodge his attacks to get behind him and chain backstab him like any other human fight until he goes phase two which is also easy. I beat him first try on NG+3. He only healed once which was whatever.

It took me longest to defeat Lumacchio of all bosses in the DLC so far but I have not seen him heal more than once in his human form and then second time as he transforms.

You will eventually get a rythm to parry his attacks, at least most of them, in his first phase. Some tips:
1. fish for backstabs - you want to rotate to your right (Lumacchio's left), stick close to him and activate fatal attack when your see the prompt, it shows while you are slightly behind his left shoulder. There are good attacks to parry, which give you opening to go for the backstab. Keep in mind that you can not do another backstab right after first one, there is some kind of internal cooldown.
2. If Lumacchio goes for stabbing attacks, it is best to quickly dodge away to break his combo chain otherwise he will keep attacking in a long and hard to parry chain.

I've seen some other people complaining about the same bug. Other than just verifying your files, the best advice I can give is to wait for a patch, sorry.

You can also really easily chain knockdowns on Lumacchio in phase 1 using the Puppet String legion arm. Just press and release L2 to pull him to you and hold L2 to punch him while he's getting pulled close to. Its a guaranteed knockdown in phase one. You can follow up with a charged R2 from most weapons since his animation getting up off the ground takes a bit. Or even heal or use a consumable. Then repeat from step 1 once he gets up for as long as your legion lasts.

you are all awesome! going back in now after verifying files. hope you all have a great day and thank you again

Haven't seen this bug myself and I did that guy phase 1 parry only god know how many times. You can try to backstab him after umbrella / red attack but backstabing him is kinda weird atm cuz in 50% of the times it will be just normal attack for some reason.

If you don't care about "honor play" just use parry stone + icarus. Stagger him, then when you poisebreak the guy throw icarus three times then do a crit then another 3 times. You should be able to deal some massive damage. This stuff works for lots of bosses.

引用自 靐：

...but backstabing him is kinda weird atm cuz in 50% of the times it will be just normal attack for some reason.
...

There is some kind of internal cooldown on backstabs. You can not get back to back backstabs unless you wait for a long time. When you backstab him, you should just punish him with normal attack after your parry or dodge his chain. You can start fishing for next backstab on his next move.

引用自 Baron01：

引用自 靐：

...but backstabing him is kinda weird atm cuz in 50% of the times it will be just normal attack for some reason.
...

There is some kind of internal cooldown on backstabs. You can not get back to back backstabs unless you wait for a long time. When you backstab him, you should just punish him with normal attack after your parry or dodge his chain. You can start fishing for next backstab on his next move.

Yeah I had a strong feeling about backstabing CD, but I am still unsure about the icon. If backstab is on CD will backstab icon appear or not? Cuz for me backstab icon kinda flashes when I try to hit the guy. Feels like backstab angle is changing with the enemy animation.

Oh, yeah, I just remembered fighting rabbit dude and "survivor" npc. Both of them are super easy to backstab and I could do this like every ~10 seconds, so pretty sure that's just angle issue.

Lumacchio has weirdly positioned hitbox. It felt to me that it was slightly off compared to his model to the left side when behind him. I had much higher success getting the backstab going from right side when facing him, ie. rotating around his left shoulder than the other way around.

This boss is truly broken indeed, especially the last phase. I even tried lowering the difficulty and it doesn't help. It clearly shows that the experienced devs went on to work on LoP 2 while the incompetent inexperienced ones worked on the DLC. This boss shows a complete lack of design skills. It's just unfair on a disgusting level.

I'm assuming you aren't using Lea for assistance for the additional challenge?

引用自 TAW Derisat Hartfelt：

I'm assuming you aren't using Lea for assistance for the additional challenge?

I think you're in the wrong thread.

引用自 TAW Derisat Hartfelt：

I'm assuming you aren't using Lea for assistance for the additional challenge?

Lea is too busy tracking Arlecchino to help you with Lumacchio.