Activate by declaring 1 monster Type. All face-up monsters become that Type.It's time for your surgery! You're going to wake up as a brand new monster! DNA Surgery is one of the earliest cards in the game. It was first introduce in the original Yu-Gi-Oh! anime series. This trap card can create major advantages. DNA Surgery can limit opponent's decks that require particular monster types and/or boost the player's monsters.
Players can take full advantage of DNA Surgery's effect to strengthen their monsters and effects. Beast-Warrior, Dragon, Insect, and Machine decks can use this card to their advantage by changing their opponent's monsters' type. Let's look at a few examples. Changing all monsters to machines will boost Machine King's, Perfect Machine King's and/or Machine King Prototype's power for each machine on the field! DNA Surgery andis a good combo for stalling the opponent.
DNA Surgery is a great side card against Bujin, Fire Fist, Noble Knights, and Spellbook/Prophecy. These decks' support cards rely on their monsters being specific type of monster. Chanting their monster type will greatly hinder them. The will not be able to use their support cards that required a specific type of monster such as Spellbook of The Master. These decks would be very limited until they are able to destroy DNA Surgery.
Furthermore, DNA Surgery prevents certain Fusion, Synchro, and XYZ monsters from being summon. These monsters require a specific type of monster(s) to summon them. Cyber Dragon Nova, Hierophant of Prophecy, and Five Headed Dragon are just a few monsters that would be locked in the extra deck.
In Closing, DNA Surgery is a pretty good and cheap side deck card. It has so many reprints that you can buy it for nothing. DNA Surgery can strengthen your forces or cripple your opponent's deck. If you're a budget player then considering siding DNA Surgery!