No,  she's  pretty  good  without  book.  Load  her  up  with  as  much  defense  and  accuracy  and  you  can  find  and  added  bonus  if  you  can  get  some  crit  rate  and  crit  damage  too.  Put  her  in  a  stun  set  and  she  will  upset  lots  of  teams  in  arena.  I  had  mine  in  a  regeneration  set  and  that  was  quite  funny  in  arena  too.  She's  so  versatile...  stat  priority...

Defense

Accuracy

Crit  Rate

Crit  Damage

These  will  do  as  a  general  build  but  you  can  add  resistance  if  you  want.  Play  around  with  her,  she  is  hands  down  one  of  the  best  champions  in  the  game.  Speed  is  important  on  all  champs  but  she  doesnt  need  to  be  smokin  fast,  around  170-180  is  a  decent  speed  for  her.

There are several ways of using her - one is offensive, focused on her AOE attack which chance to stun, in which case you probably do want to book that to reduce the cooldown and increase the stunning chance. The other is more supporting, as a dungeon carry. In both cases, you'll want to push her defense as high as possible (def percentage gloves and chest) as well as getting sufficient accuracy (not only for the stun, also for the speed and TM reduction on her A1), but in the first case you go for crit rate/damage as tsd said, in the second you give her more HP and resistance. As for speed, she doesn't HAVE to be super fast, but considering her passive, the faster she is, the more she'll heal, so it's still worth putting effort into her speed. 

Definitely book her. Since you seem to be in early game, she will help you in all content of this game. 

Make her fast and tanky with some accuracy then your good. 

I nearly fully booked her and put her in relentless gear so that she cycles through her abilites more quickly. So far the results have been great. You don't have to book her, but getting her A2 to land more quickly and to have a shorter cool down really helps in progression.

Scyl is great and booking her will definitely help a lot. Like what the others said, build her with speed, survivabilty, and accuracy. Using other sets like Relentless is also a good idea, but only if you can get the proper stats with them. 

I don't think I'm in early game , i have level 58

I completed  alle dungeons  

except dragon, spider and fire knight.

i'm in

dragon: 18 d

spider: 10

fire knight 14

I'm in camaign nightmare valdemar strait now 

I don't know if SCYL OF THE DRAKES  can mean anything anymore, isn't it the case that I should first lift Alure stronger and at level 60, she helped me quite well, 

she ensures that the opponents do not get a turn with the last dungeons. For healers I have zelotha and Apothecary.

zelotha has a shield set, and provides quite a large protection buffer and Apothecary gives me much more speed and heals

I have cardinal, and corgorab for raising the dead, she brings them all to life at once . SCYL OF THE DRAKES can only one raising out the dead at once.

Moutain King, and Kael are the biggest damage dealers.

Best way i fround to build her Defence stacked her hits based on defence next ACC for her stunns then speed and to me crit rate and damge dont matter she is not a AOE nuker and good luck :)

It's quite difficult, because it has to have a lot of acc, and def, it has to be fast enough, and must some critrate and CD at the same time. but then you quickly run out of hp again and she quickly dies. If you give them def gloves, you will quickly fall short of the crit rate

quite a lot, if you have upgraded all gear then it appears that you are short of a number of properties, then you have to switch everything again, but then you come up short in other properties .

and it will cost you a lot of silver again 

and I get so little good gear. most I have to sell because it is worthless. Many chamions don't even have gear, because I don't have enough decent gear.

Because I have too little energy every day, I can also gather very little in the dungeons. 

I also have to waste energy for upgrading the champions 

and the worst part is you lose a lot of silver due to the failure of upgrading your gear, and because you have too little energy you hardly get new silver 

This is the definition of early game, imo.  

All dungeons completed? No, only golem LOL.  The keeps/mino don't count those are very early game.  Beating dragon20 is getting you closer to middle of early game.  Once you have or are very close to Arbiter you are mid-game.  You should spend 0 energy in NM campaign.

Have finnished level 20 dragon thanks by SCYL OF THE DRAKES 😀

Are her hits damage based on defence ? Not critrate or Critacal Damage?

I will be getting scyl in two weeks time. But legendary books are quite rare for me (i get them off CB only)

And i pulled dracomorph during the weekend event.

Would you give your books to scyl or draco? 

Draco for sure. I nearly fully booked Scyl and I plan to use her in all content except CB. Draco, on the other hand, can be used pretty much everywhere, particulary CB. If I got Draco today, I'd spend all my books on him in a heartbeat. 

Thanks, it will take me weeks to level, book and do masteries for draco, so deciding who to focus on is a big decision :)

Will focus on draco thanks again

Where or how to get Scyl of the Drakes ?

...from Ancient Shards or the 180 day login reward