A second monster with more ATK or DEF than your opponent's strongest monster
Equip your second monster with "Raregold Armor". Then attack directly with "Drillago". Since "Raregold Armor" only allows the opponent to attack the equipped monster, your "Drillago" is safe as long as the equipped monster has more ATK or DEF than all of your opponent's monsters. This way, you can keep attacking directly with Drillago until you win.
Combine this card with "Mist Body" and "Kaiser Colosseum". This way, it can attack the opponent's weaker monsters, then attack directly without fear of being destroyed.