Forum:Help! Need to improve Spellcaster deck!

I've been on hold with duel monsters for a while now. I was always into the original Yu-Gi-Oh! and I have stopped playing after I entered Junior High. I am now a sophomore getting back into dueling. >.<' It's been a long time now that I think about it, what made me get back into this is that now we're starting competitions at school when there is nothing to do and my brother wants to get my title as the "Queen of Games" in our neighborhood. The "King of Games" is leaving for the army this year so I'll be at the highest rank in our neighborhood and the others want to duel me for my title now. I sold my old deck and kept my most valuable cards but my youngest brother lost them. They were my Dark Magician, Dark Magician Girl, Magical Hats, and basically the original Spellcaster monsters, spells and traps. I also had my Harpie sisters, but he lost those two. I just bought the newest spellcaster deck, but I want to regain my old spellcasters-that's going to be difficult though. I need to know how to make my deck stronger though. New, Current Deck:

Monsters:

-Defender, the Magical Knight -Apprentice Magician -Magical Marionette -Summoner Monk -Hannibal Necromancer -Disenchanter -Dark Red Enchanter -Crystal Seer -Mei-Kou, Master of Barriers -Mythical Best Cerberus -Blast Magician -Skilled Dark Magician -Royal Magical Library -Magical Exemplar -Magical Plant Mandragola -Old Vindictive Magician -Breaker the Magical Warrior -* Endymion, the Master Magician

Trap:

-Pitch-Black Power Stone X2 -Magician's Circle

Spell:

-Field Barrier -Twister -Spell Power Grasp -Enemy Controller -Terraforming -Giant Trunade -Magicians Unite -Magical Citadel of Endymion -Magical Dimension -Magical Blast -Book of Moon


 * FYI-my brother took some of the cards since he bought me the deck -_-