What A Skill should I give my +Atk -HP Tana?

What are you planning on using her for? If you're planning on using her for Arena, then the HP loss from Fury is minimal. Her best A skills, if you're not using a Firesweep or Brave Lance Build, are Fury 3, Life and Death 3, or Close Def 3. You can use Deathblow if you're using a brave lance.

I have the same Tana! tbh her best A skill with her standard weapon is Fury3, you can run LnD3, but that is more for Firesweep! in other words this are her best sets:

Fury3/Renewal3
Life and Death/Desperation o Hit and Run
Distant Counter/Blue tomebreaker3

I personally run Fury3/Renewal, but my Tana is +2 and with summoner support, so.