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[WH40k] Who wins in a battle between Tyranids and Nurgle?

I mean, who ends up wining the most? do the absorbed plague marines disappear from the warp? does the ammount of death and virus/plague/things to rot make Nurgle stronger?
Do they work symmbiotically?
gpt
We will assume for the sake of 40k – the Nids attack a series of plagued planets, as Nurgle is happy to let his gifts fester while the Nids don’t hang around once the deed is done. 

At first? Nurgle gets rolled. Like it’s not even funny – the first 2 months see his planets get eaten with little to no resistance. The Shadow in the Warp makes it hard for demons to get a grip on realspace and things go poorly. The basic poxes and plagues are mildly effective until immunities are evolved. 

Fortunately Nurgle understands life and death and ebb and flow. He’s not cocky and won’t be goaded into throwing forces at unwinnable engagements. The 3rd planet falls, but is defended heavily. The xenos aren’t entirely aware of it – but once the initial defenses were smashed the survivors seemed to offer themselves to the tyranids, however this was likely not noticed in the ensuing blood bath. 

The fourth planet meets a similar fate – but the 5th… things go differently. Bioweapons on the nids start failing – talons and pincers suddenly begin to rot off. Synapse creatures slow their advance and collapse – feral tyranids tear into eachother. The Norn Queen realizes the latent infection and begins sifting through the DNA – purging it and making healthy nids. The swarm is slowed but not broken. However down on the surface the plague nids are driven insane and lash out at anything (healthy nid and chaos forces alike) and the fighting devolves into a bloody free for all. 

As the nids redeploy they are faced with cutting through their infected brethren to get to the chaos forces – which they do. While ferocious the plagued nids are crippled and slower. They last for days before their broken husks litter the ground and the newly minted nids charge forth once again. As the nids relentlessly advance the corpses of their infected brethren rise from the dirt and mire. Much slower now – their bodies barely held together – limbs dangling or missing entirely. While not nearly as ferocious they are Nurgle’s children now, and they serve but one purpose now – to protect their master. Each one shambles into the fray – clinging to whatever enemy forces are nearby and exploding in a shower of acid and puss. The virulent toxins infecting the healthy nids – while they can ignore it in life once felled they will rise up again as shambling suicide bombers eager to spread Nurgle’s gift. 

The event perpetuates for weeks – until the losing battle is realized and the nid forces withdraw for fear of losing too much biomass. 

Nurgle wins a narrow victory – and zombie suicide bomber plague nids terrify everyone. The hive fleet goes to eat an agri world or something.