Cyber Dragon CRV-EN015
If there is a monster on your opponent’s side of the field and there are no monsters on your side of the field, you can Special Summon this card from your hand.
Why Cyber Dragon? because if you're second, almost all the time your opponent puts down a monster on the first turn and you can special summon a 2100 machine on your first turn.
Other pros to cyber dragon include, light -chaos food, 2100 attack is good for a lv 5 monster, and the fact its a machine.
Off topic: I forgot to add the COTD part