Here's a guide how to clear the stage. This is probably where most player would experience difficulty spike. Especially casual phone player.

I would suggest player clear this stage is quick as possible to avoid repeating my mistake. The stage SCALE WITH YOUr INTERKNOTE LEVEL. meaning that if you level 39 the stage would show level 38 difficulty.I personally hate this stage and boss design.  But the moment you clear level up stage 40. The new difficulty is level 48. Meaning you need to make sure your agents are at least level 50.

Personally I hate the boss design. It is not phone game friendly. Zzz don't have manual lock on target. It will always target the closest enemy. So having two identical enemies that can teleport around and switch places is annoying. The problem is made worst that you have to kill BOTH in a short window of time before they revive and heal each other. You are essentially DPS lockout if you can't kill them quickly enough. I've try damaging them close to death without killing one. But since we can't manually lock on one target boss, most agents attack are aoe and they stand next to each other. You'll accidentally kill one early. Starting the revive process. If you fail to kill the second boss before the first one revive. Congrats the game become a stupid loop. Your phone will heat up due to the amount visual garbage on screen. 

Anyway if made my mistake and are not a hardcore gamer elden ring type of guy. Just wait till you have level 60 agents max upgrade DPS role to clear the stage. Or use a computer.

Rally Purge, Phase 2 Twin Marionettes