build 1: too many eagle tunes, use high boost beta to save cost.
High boost beta + life + life: 30 HP, 2fly, 25cost
eagle + eagle: 30HP, 2fly, 30cost
natascha is an air-hunter. Airs tend to be in the sky. shooting them from the ground causes problems. Using the "short boost" cartridge allows natascha to place herself in the air quickly, and then fire from less vertical distance, increasing her chances to hit.
For a fly-based build, the space bar can be held afterward for movement. For a walk based build, it really can't.
I highly suggest taking short boost on natascha for this reason, regardless of what stat you tune, because it allows her to shoot at airs better.
you have a huge emphasis on HP, at the cost of utility. I suggest dropping HP to get extra carts. consolidate tunes to free space. Natascha can pull off a fly-based build without handhelds rather easily.
https://i.imgur.com/GyVorIe.png
extra capacity is for accel roll. There's a few bad tunes and I can get about 10 more hp if I redid the build, but the point remains.
500+ HP really isn't needed on her. anywhere between 450 and 500 is fine. 530 is excess and you are losing out on useful carts when you use your limited capacity to get extra hp.
If you do walk or fly is up to you, there's pros and cons to both, but I feel that neither of the presented builds are good.