Dark magician is the ultimate wizard, but he needs a help getting there.
Magician's rod is the searcher to get the pieces needed for dark magician depending on what you already have.
Inspector border is there cause you want your opponent to use as little monster effects as possible. He may take up a normal summon but its a fair cost for a good effect.
Dark magical circle is for setting up the draw phases but you usually want to use that card last. Use the banish part of the effect to get rid of stuff on your opponent's field.
Secret village is great at stopping the opponent from playing assuming they don't have any spellcasters otherwise it's better to side out. Side note is make sure you can always have a spellcaster out there otherwise you will screw yourself
Card of demise, starting turn you want to set everything and use it. If you have inspector border then summon or magician rod summon and add illusion magic. Drawing 3 cards for free is ridiculous. And I've found playing magician with floodgates is the best way to go. And you want to make sure at min you are discarding 2 DM during your end phase.
Pot of duality is to try to get cards you already haven't used or to get cards needed for later.
Spellbook engine is a good engine, just more draw power to mill through the deck.
Illusion magic is meant to be used after you use card of demise so you can add two magician to discard and have your graveyard set up.
Dark magic expanded is honestly there to use the second effect and it's good. To protect your stuff from being destroyed is great.
Eye of timueas is great to bring out the extra deck magician for the situation. Dragon knight is great at protection and having another magician in the field/gravyard. Amulet dragon is for decks that recycle spell and trap cards from the graveyard so you can flat out banish them. Dark paladin is for dragon decks, that negating a spell card is always fun. Dark calvary is for more or less like amulet but if your opponent has a defense position monster its as good as game.
Foolish burial is to get a DM in the graveyard as soon as possible bit if all
Summoner art is if you haven't seen rod but need dark magician quick(can be replaced with upstart goblin)
Dark inheritance in to add whatever magician card you're missing.
Summon limit, no way your going to summon more than that except on really rare times.
Skill drain, stop those effects.
Solemn strike is to stop hand traps, monsters activating an effect or special summons.
Judgement the best no card
Eternal soul is the best card in the deck in my opimion, always special summoning a DM and they can't destroy it other than battle (or destoying the card) you have to protect the card at all costs
No much to say about the extra deck other than link spider is there if you have to make one dark magician work. And beat cop is to protect eternal soul once.
This deck's weaknesses are called by the grave(banish dark magician), evenly match, mst, unaffected by card effect monster/ can't be targeted, and monster stronger than 2500. You can still do stuff just makes it harder.