As we all know, after 3.1 (correct me if I'm wrong; I don't think that's the right update patch), Raw Nerv's SA has been modified so that she'll gain Enrage when dropping to 50%, just like Haste before, but also inflicts Death Mark when dropping below 25%.
This significantly increases her utility, given the permanent debuff she inflicts. The best situation where she can be used would be in defense positions, and placing her as the first opponent to face. Once Death Mark kicks in, the AI will hit harder when blocking. Sure, it's a low damage increase, but it feels greater against strong foes, especially if you used a character with low HP, defense or block prof. to beat her (and by beat I mean weaken her enough, because it could always happen that she ends up killing you before you do for whatever reason).
On the offense part, given Painwheel's glass cannon cathegory she'll do relatively fine by herself. Not to the same extend like Buzzkill or Fly Trap, but she'll still hit hard. But what if you want to gain the Enrage and Haste? Well, naturally you're gonna have to get damaged, which is not reccomended but it's the only way. There are workarounds, though. The damage itself could be taken with a Bleed debuff, or near a Bio-Exorcist, that way you'll get hurt but won't flinch from it. In addition to that, if you carry a healer like Surgeon General (I can't because I don't have her :"( ), preferably with the Trauma Center marquee, you can recover HP above 50%, then get a few more hits, if possible from block damage, so it's mostly negligible, until you reach 5 Enrage stacks and proceed to kick the opponent's bum. It could also be done before the patch, but was way risky due to the 25% HP mark.
Alternatively you can rely on recovering scratch damage, but it's a far less reliable strategy than the previously stated. You can have Scrub and Rerun on your team to speed up both scratch recovery and tag-in cooldown, but with or without it, it's a far slower method, and one that cannot be reccomended.
As for the Death Mark uses for offense, the most useful teammates would be those who have excellent crit damage like Dragon Brawler, or crit rate like Sheltered or Bad Hair Day. Purrfect Dark can also benefit out of this, but because she also inflicts this debuff, there's not much of a point in pairing them together.
Last but not least, which marquee suits Raw Nerv best? Much like other Painwheels, it comes down to preference; personally I picked Tainted Blood because given her SA, it's best to just gain the buffs and inflict Death Mark as early as possible, and because she has an ok base HP for a Painwheel. Also, I picked it before Grudge also gave Armor stacks, so...
Ultimately, while there are better variants overall, Raw Nerv has managed to become a decent defensive variant, who can also be good at offense. She'll punish those who underestimate her.
Plus, from a personal experience, she's my prefered fighter in the Chaotic Evil node on Rift.
