Just keep destroying the field card. Pretty much cripples them as well as wipes their field. Also sphere kuriboh can’t be destroyed and Phoenix has low defence.
Just play an Ojama deck. They'll get their 200ATK Yaksha out, which can't do anything, and then Ojama Knight can seal the other two zones, preventing Nephthys's special summon.
No legit Nephthys would fall for that poor set-up. It literally relies on Field spell and them NOT having a common counter Trap-like to destroy the combo.
LMFAO. Every Ojama deck I went up against from gold to legend couldn't stop my nephthys deck. Owned all of them. Even when they brought out Ojama King, I got replays for proof if you want.
The only times I countered it was with either “symbol of duty” or “Autonomous Action unit” these cards will make that deck look like a joke, unless if they have more than 2 Phoenixs. But it’s still satisfying to use their godly card against them.