Discard cards like Kidmodo, or Bacon Saver to setup some of your plays for the later turns, or use Sword of the Deep-Seated so you can keep recycling it to keep destroying your opponent's monsters. Needle Sunfish is good if your opponent has 2 or more monsters already out on the field so you can use its effect.
Best card to use to protect it is Super Rush since it can work on your other monsters as well, along with being able to use it offensively. Continuous Destruction Punch is good if you play a defensive deck, but using it can let your opponent know of your play, and end up switching your opponent's to defense position.
If you just normal summon Cyber Gymnast with some back row, your opponent might switch them to defense position in fear of it getting destroyed. Best case scenario is if they switch all of their monsters to defense, allowing you to destroy them all with Tragedy.
Discards for cost
Destroys your opponent's face-up Attack Position Monster Cards
Where can i get the second one except alexis lv up