The Magicians Bookkeeper

[Hydra Iron Man]

 

Every time you Special Summon a Spellcaster-Type Monster: Draw 1 card. You can Banish 1 face-up Spellcaster-Type Monster during your End Phase to draw 1 card. If this card is removed from the field by a Spell or Trap card: Discard 3 cards from your hand. If this card was destroyed by battle: Draw 1 card.

[Trebuchet MS]

Every time When you Special Summon a Spellcaster-Type monster: Draw 1 card. During your End Phase: You can Banish 1 face-up Spellcaster-Type monster you control; during your End Phase to draw 1 card. If this card is removed from leaves the field by the effect of a Spell/Trap Card: Discard 3 cards from (or your entire hand, if less than 3). If this card is destroyed by battle: Draw 1 card.

Plusses, plusses out the wazoo. I'm not fond of this when you can get card advantage repeatedly, or at the very least, make Special Summoning cards float. Yes, the discard 3 might be a drawback to offset the ridiculous advantage you get, but under most circumstances you can dodge that by, after a Special Summon spree, having this card banish itself during the End Phase to draw 1 last card, or purposely ramming itself into a stronger monster the opponent controls to get another card. Not to mention that it can also be used in Synchros and Xyz Summons to avoid getting forced off the field by an S/T, or the discard 3 downside can be mitigated by using everything you've drawn.

 

I would recommend tacking on a "You can only use 1 (card name) effect per turn, and only once that turn." restriction to greatly rein in the amount of card advantage to be gained. We can also do without the discard-3 drawback as there's already many, many ways to circumvent it.

[LeLukeX]

Hmmmmm
 

I like it.  

Too little restriction though.  Removed by an S/T is... Like what S/T really?  D Prison and MF are all avoidable.  He can't be Bottomless'd.  Solemn doesn't force the Discard 3.  BTS doesn't remove it.  That leaves TT and CED as the only Traps that can kill this card... TT could be forced at an unwanted time.  
 

Dark Hole is there too but very few players use that this format.  Plus you can protect this card with both Lance and that one Quickplay that protects a Spellcaster from Spells or Traps (you pick on activation).  

 

You pretty much put a pressure on your opp to kill it via mosnter eff, which isn't fair IMO since it probbably already plussed you.  This card draws too much 

[Peridank]

This card reminds me of a Spellbook monster posted bout a month ago... like it was stated too much draw power. I don't like weaking effects once there set, so in my opiniln, don't nerf and make this cards discard effect do both battle and trap. But then make SS a once per turn and SS entirely too summon. BTW it's spelled "Magician's Librarian" sorry to be a grammer shark but it would look more realistic that way.