Well, not a significant number. Guess I'll try to give you a breakdown of what to get then.
As another note, very few attacks of Scythes actually use the Att
Disclaimer : Not an Evie, this might be totally wrong.
Trying to use the DB's skill calculator for the first time to answer one of these, since I'm getting lazy at manually doing the math.
http://vindictusdb.com/skill-calculator?i=Evie#6:0:7;10:0:7;12:0:6;12:1:1;1:3:1;1:2:1;1:1:1;1:0:1;4:0:1;4:1:1;6:1:1;8:0:1;9:0:1;10:1:1;10:2:1;10:3:1;14:0:1;14:1:6;14:2:10;16:0:6;18:0:3;18:1:1;18:2:1;18:3:1;18:4:1;18:5:1;20:0:10;22:0:1;22:1:1;22:2:1;22:3:10;24:0:1;24:1:7;24:2:1;24:4:6;24:5:6;24:6:1;24:3:1;28:0:6;28:1:7;30:1:1;30:2:1;30:3:1;32:0:6;34:1:1;36:0:10;40:1:10;42:1:6;42:0:1;40:0:1;52:0:1;56:0:6
Notes:
Cloth Mastery is taken to r9 on the assumption you will be using the Wonderland set as your endgame set. Light/Heavy will be relevant if you intend to use Mhara, Fallen Angel, or Black Pearl. Likewise Scythe Mastery is taken to r9 on the assumption that you will be using a Lv. 60 Scythe as your endgame weapon. Take it to r6 if you intend to use a 70 or 80 Scythe.
Int Mastery and Magic Mastery are both taken to rA only, as their AP costs increase by a significant degree after that point. Getting them to r6 is good, but costly.
Insane Reaper is prioritized to r6 as it's a party wide buff, which means in parties with other Evies - the stronger IR takes priority. Getting it to 6 ensures maximum duration, effect, and prevents you from failing to use your IR due to a better IR being already used.
Mark of Death, Bloody Thread, Blade Shift, Demon Splitter, Life Drain, Spirit Bind, and Sacrifice are the ones I'm kind of iffy on. If someone who knows Scythe better wants to chip in, this is probably the place. They all kind of have linear AP requirements and you'd probably be best maxing them all as I believe they're all used extensively, just it's kind of hard to decide the exact cutoff in terms of AP payoff.
Likewise, Magic Critical Hits falls under the same issue in that it's an amazing skill, it's just kind of linear in it's AP cost which means it's hard to say "stop here until you have AP".
Campfire is a nice skill, get it to A later on as it's cheap. But Evie is probably the character that cares the least for the camp buff as she has like no Def anyways.
Combat Mastery is taken to D as that's a prerequisite for Smash Mastery, which is a great skill as it affects all smashes.
Standing Endurance is taken to 9 due to the quick rise function being added, taking it to 6 is also good for the stam decrease but I'd just keep it there until you finish everything else mentioned.
RG is kept at F for two reasons. One, your other SP skills are good (Sacrifice, IR) and should take priority. Two, RG skill ranks do not add significant damage to RG, so it's not very AP efficient. Take it eventually, but it's pretty low priority.
Eagle Talon r9 doesn't have many practical uses, so I kept it at rF. I can think of some (i.e. breakoffs), but it's not very important. Get it eventually though.
And unless I'm wrong, I think Scythes can still use alchemy kits, so Mana Pistol is still a great solo tool.