Nekima has always been about Shock and Awe...speed and applying damage where it needs to go to overwhelm the opponent before it can use its full strength. It's almost a full melee keyword, and the traditional "bad guys" of Malifaux. The idea is that you have the speed to apply damage where it needs to go, and even if your models die, they'll wound back their attacker with the black blood ability, so getting out of a melee fight with Nephilim unscathed is usually hard. Nekima and the Mature Nephilims can hit hard if left to do their thing. The Youngs are your go-to shock trooper.
It's certainly not the toughest group, but if things go well, you'll regenerate just enough to carry on to the next prey, and inflict more damage. The grow mechanic is not entirely a strategy imho, it's something you carry in the back of your mind in case the right opportunity arises...yet it will scare your opponent (especially if you get a mature up). But that's a bit of a snowball effect, if you're able to grow bad stuff, it's because the game is going your way already. There are some models who will make this easier.
The utility comes with a few models namely Hayreddin, the Black Blood Shaman and the Lilitu...and to some extent Nekima's pig (totem). You'll need to balance your crew between Smash, Scheme & Support to get a good momentum. But overall the keyword is not subtle, which means the opponent can easily know what to expect, they're in your face. We've found it a good one to teach the game because of that.
Lastly, the versatile hybrids of the Neverborn are kind of part of this keyword...at least in theme, because they've been created by Nekima, so if you like Blood wretches, Angel Eyes, Maurice and Tuco...they can bring more variety to your tactics.