Forgive me if there is already a thread about this but i wasn't able to find a thread.  

I also do apologize for the formatting, this is my first time to create a post like this so i hope you do get the idea that im trying to convey here. Help/Advice is greatly appreciated. This post leans more on helping you to decide what A Skill you should put on your blade user.

So during a TT run i thought about switching Fury on my Nino for another skill, even if its just a niche. I tried putting Defiant Speed ( 7 Spd when <=50%) and it was a great success.I also wanted to make my blade user to be independent of buffs when needed.

Not only do i get an additional 7 damage, i also pretty much double every unit found in TT now. 

So here are the stats: 

TAKE NOTE: ALL OF THIS ASSUMES THAT NINO IS AT OR BELOW 50% HEALTH FOR DESPERATION AND DEFIANT

For Fury 3:

WITHOUT BUFFS:  

Without Moonbow: 77 wins · 20 losses · 61 draws 90 favorable · 25 unfavorable · 43 other

With Moonbow: 95 wins · 17 losses · 46 draws 100 favorable · 19 unfavorable · 39 other

WITH BUFFS ( 4 Atk, 4 Spd, 2 Res - Will be used for all)  

Without Moonbow: 144 wins · 3 losses · 11 draws 144 favorable · 3 unfavorable · 11 other

With Moonbow:  148 wins · 2 losses · 8 draws 148 favorable · 2 unfavorable · 8 other

For Defiant ATK 3:

WITHOUT BUFFS:  

Without Moonbow: 106 wins · 20 losses · 32 draws 131 favorable · 20 unfavorable · 7 other

With Moonbow:  113 wins · 16 losses · 29 draws 136 favorable · 16 unfavorable · 6 other

WITH BUFFS:  

Without Moonbow: 137 wins · 5 losses · 16 draws 152 favorable · 5 unfavorable · 1 other

With Moonbow:  138 wins · 4 losses · 16 draws 154 favorable · 4 unfavorable · 0 other

Defiant SPD 3:

WITHOUT BUFFS:  

Without Moonbow: 113 wins · 12 losses · 33 draws 140 favorable · 13 unfavorable · 5 other

With Moonbow:  131 wins · 9 losses · 18 draws 144 favorable · 9 unfavorable · 5 other

WITH BUFFS:  

Without Moonbow: 144 wins · 3 losses · 11 draws 154 favorable · 3 unfavorable · 1 other

With Moonbow:  148 wins · 2 losses · 8 draws 156 favorable · 2 unfavorable · 0 other

And Finally, LND3:

WITHOUT BUFFS:  

Without Moonbow: 97 wins · 17 losses · 44 draws 130 favorable · 19 unfavorable · 9 other

With Moonbow: 117 wins · 12 losses · 29 draws 138 favorable · 12 unfavorable · 8 other

WITH BUFFS:  

Without Moonbow: 148 wins · 3 losses · 7 draws 154 favorable · 3 unfavorable · 1 other

With Moonbow: 149 wins · 2 losses · 7 draws 156 favorable · 2 unfavorable · 0 other

ANALYSIS:

Now just for attacking, the absolute winner is LND3 at 149 wins WITH buffs and a Moonbow proc.  The weakest performer is Fury with no buffs at 77 wins.

For RAW Damage output, i put in this table (Accounts for Gronnblade and 50% HP)  

While Defiant ATK does have the highest raw damage, it is also has the lowest speed among the group, giving way to Defiant Spd and LND3 for highest potential damage.

Now here is where economy takes part.

Here are the Defiant SPD 3 owners:

5*: S!Camilla,Lucina,Robin  

4*:Raven

Though Raven has Defiant SPD 3 at 4*, making him the best choice for fodder if you have him.

For Fury, we have:

5*:Bartre,Eldigan,Jagen,Legion  

4*:Hinata

Here we have Hinata for our 4* counterpart.

Defiant ATK Users are:  

5*:Gaius,Karel,Lyn,Odin,Ryoma  

4*:Ogma,A!Tiki

We have two 4* heroes that have Defiant ATK 3.

LND3 Users are:  

5*: Hana,Jaffar,Minerva,Zephiel

No 4* hero has LND3 Sadly.

CONCLUSION

With LND3 being the "best" performing inheritance, it is also the most costly to obtain.  

Every A Skill except fury will have to require careful baiting OR swapping Draw Back with Ardent Sacrifice, so keep that in mind.

If you want to rely less on buffs and support units (Which i don't get since you are using a blade unit), you will see most success with the Defiant skills. Though extremely situational, there are times wherein you may want a blade user to temporarily separate from a group or what not.

For "Budget" builds, Defiant Spd and Atk should be the easiest to obtain, and if you have more important units to put Fury on, Defiant Atk/Spd isn't so bad to put on blade mages.

Personally, I put Defiant SPD 3 on my Nino because i found that any unit she can kill any unit she doubles. There are some situations that i find myself wherein that Nino would be able to kill a unit if she had 1 more speed.This happened too many times and upon replacing her fury with Defiant Spd 3, i am not placed into this predicament anymore.

Now this post has been all over the place with numbers and almost incoherent rambling, but i hope it helps you.