October Novel Prep Challenge

Guys,

I have a question about today's assignment. The question is this: How many is too many? Here is a list of characters that will be appearing in my novel:

The Core
Tocanema Tia Spellman-
Landon Russo-
Rosabelle Isla Fairmont-
Telk Lee Brook-
Stella Russo-
Starling MacStone-
Seth Lucas Wright-
Michaki Sadiki-
Ryan Shen McBurr-
Danny Foreman-
Miley Potter-

The Caretakers
Arianna Sadiki
Seth Wright 
Sasha McChey
Lucas Michaels Fairmont
Darik the Freed House-Elf
Neo Spellman
Franco Spellman
Gabriel Lupin
Maxwell Lance Sinclair
Lance
Leo Potter
Brennan Dawson

The Bad Guys
The Dark One
Mikhail Dimitrov
Zia Zebo
Victor deVegy
Khalid Onaris
Shadow 
Jackson Russo-

Others
Tarik Sadiki
Nathalie Lupin
Marco Spellman
Leo Spellman
Katrina Spellman
Anthony Mirabeau
Dempsey McBurr

How many of these need to be included in today's lesson? I have detailed bios on all of them but some were written about in the first two novels. While others are finally being introduced in this one. Help, Please?