Enemy Controller alone can already be good for protection, but it also lets you make quick plays if you already have the other supporting spells.
Summon Legion the Fiend Jester, Enemy Controller to take control of your opponent's monster. This lets you pick up a Dark Magician from your deck. Use Ancient Rules to summon Dark Magician. If you have Dedication through Light and Darkness, then you can attack 3 times to potentially end the duel.
If you also have a DMoC in your hand, then you can go for a more safer play by summoning Legion, use Ancient Rules to get Dark Magician, then tribute summon into Dark Magician of Chaos through Legion's effect. Alternatively, you can use Enemy Controller to take control of your opponent's monster by tributing your monster other than Legion before tribute summoning into DMoC. This will let you bring back your Enemy Controller during your end phase, but you will not be able to set it right away. This is safer than the first option if you are unsure about your opponent's set spell/trap cards, since your opponent's monsters are tributed away, they won't return to your opponent.
Using a combination of Birthright and Dedication through Light and Darkness, you can essentially attack up to 3 times or more in a turn. This strategy allows you to attack your opponent unexpectedly, which is good to use once you know your opponent can't stop your attacks, and if you can end the duel if you do it. Use any monster that you have to attack and check for your opponent's backrow, if they don't have anything then activate Birthright and special summon your Dark Magician, then Dedication through Light and Darkness into DMoC for another attack.
Brings back your DMoC if it leaves the field. This will also activate DMoC's effect to return a spell from your graveyard.
Other useful skills
Roll 'n' Boost Can be used each time your Life Points decrease by 2000. Show 1 monster card in your hand to the opponent and roll the die once. The Level of the monster shown becomes that of the die number until the end of the turn.
What about Dmoc with dimension gate and return from the dark relm and birth right for dark magician. U wanna summon Dmoc a lot so u can abuse his spell retrieval so return from the dark dimension is his best support
AoD (if you really really want to build either Daedalus or DMoC deck, i'll prefer Daedalus first). But if you want to play using more competitive deck, Ancient Gear could be a good choice for new players