X-29 HP

I wanted to play Dauntless and Fighting Fit, so I asked myself who has an HP boost in their kit? And when I realized this gal with a healing factor, who loves to ready, makes the list, I knew it had to be her.

You could get up to 29 HP if you install every HP upgrade including Front Line Specialist (though you really should take Combat Specialist instead since she reliably makes multiple basic attacks per turn). Goal is to always have 11+ HP so you can trigger those above-starting-HP cards. Beyond that, do your usual X-23 stuff, getting off multiple enhanced attacks or thwarts every turn and also heal a lot (yourself, your fellow heroes, and your X-men allies like Honey Badger).

Mulligan priorities: Adamantium Lacing, Pain Tolerance, Endurance, Specialized Training. Save Symbiote Suit for when your crew is built up.

Other cards to consider: I made this deck before Defensive Conditioning and it's an excellent option, but you actually might not want Laura's DEF to be TOO good. She wants a little bit of damage to sneak through to her so she can ready back up on the villain phase with her Living Weapon hero response. You could use it in place of the Symbiote Suit and save yourself the headache of that extra encounter card, but then you're not getting the +1ATK/+1THW it offers, which she gets to take advantage of multiple times per turn. If it's a minion-heavy scenario where you expect to consistently get attacked multiple times per turn (even though you have +2 Retal gradually clearing them out), you might be able to get away with both. What would be ideal is an Aggression teammate who can play Aggressive Conditioning on to you since she loves to make those basic attacks!