Solo it with your friends strongest servants. You can use servants like Mata Hari to skill seal him, making him unable to use his Reloading Humanity skill.

Alternately you can sacrifice your front line, use Castoria to survive the NP or use buff block and evade/invul it. It's pretty straightforward. I don't know your roster so I won't give DPS servant advice.

Get a strong Heracles off the support list, stick him alone in the backrow. Frontrow will be three good servants to be sacrificed. Let them die, Heracles jumps in, does lots of work. If he dies, revive.

Yeah the standard way of beating Goetia was backline herc, 3 frontline members to damage him as much as possible before they all perish and Herc with bond CE solo's him. Just keep going BBB over and over and IIRC the best mystic code for the fight is atlas mystic code for one turn of invuln and the 2 turn cooldown reduction on Herc lets him evade and guts again from his skills.

Geez, there are still quite many people who didn't know that skill seal completely nullify Goetia's skill. I guess there's still much to learn.

Heracles/cu alter

Or you can just use your normal team and spam leyline stones