[TIP] NEGATE YOUR OPPONENT'S MONSTER EFFECTS In a Duel, your opponent will often rely on Effect Monsters as part of their strategy. Using a card like "Dark Ruler Ha Des", that can negate monster effects, can be a great advantage. "Dark Ruler Ha Des" negates the effect of any monster that is destroyed as a result of battle by your Fiend-Type monsters.
If it attacks your opponent's face-down monster and destroys it, any Flip Effect will be negated. "Dark Ruler Ha Des" also stops the effects of monsters that activate when the Effect Monster is sent to the Graveyard, such as "Twin-Headed Behemoth" and "Sangan". There is a drawback to "Dark Ruler Ha Des", it cannot be Special Summoned from the Graveyard, so once you Summon it, be careful not to let it be destroyed.