Using a cosmic brings 3000+ health back to slot 4.  I am sticking with cosmic might on one slot if you want put a movement reset on another cosmic item since X-23 still get a single sig charge from that.  I don't enjoy watching my skill bar constantly so i will use anything except that deflect push on dash.    If your having survival issues or need to be sneaky in danger room drop Cyclone Kick and replace with Covert assassin and switch talent 3 to unexpected recovery.  For more Survival use the Shield legendary.  I keep one in my stash and switch back and forth as needed. Shield is actually the best starting point until you get everything sorted out, but in the end the axe is better once you have cosmic artifacts, an armor catalyst, and a cosmic slot 4 , videos of build in action at link below. I only assigned 200 infinity points per stone because at this time that is more realistic than the 500 allowed on this site for most players at this time. 

Rotation sigx5, rending leap,  crimson sweep, rip to shreds, disembowel, sigx2, cyclone kick (if available) repeat forever.

Below is my current big dummy vid 1:38

https://youtu.be/wkLLUyvDVAo

CDR survival with current updates

https://youtu.be/d180HI6osJE

 Below is a video of contagious CDR (older vid using Shield)

https://youtu.be/5StbCLjHIO0

Here is cosmic trial with 0 infinity points used

https://youtu.be/aH7m_Ammf5k

5 minutes in cosmic midtown. 

 https://youtu.be/oHsH9KkEnQ0