I read the rulings and I saw that it's last effect can't be reset by flipping, returning to deck, returning to hand, removed from play and returned or destroyed and special summoned. But, what about skill drain. That last effect would only count in the graveyard. However, wouldn't it "forget" that it went to the graveyard if it was returned with skill drain and continuously be able to be returned???? I'm sure someone sees how my mind could think something like that would happen.

skill drain wouldn't stop it's "can only be used once during the current duel" limitation. his special summon is a graveyard effect and there is no "effect" for skil drain to negate that remembers how many times it's been used.

hmmm... I don't really understand your explanation. Its effect to come back activates in the graveyard is right. I really don't understand what you mean "there is no "effect" for skill drain to negate that remembers how many times it's been used." It says it right on the card it can only come back once; however, once its on the field that effect should be negated and then once it gets back into the graveyard its effects would come back. I suppose it could check itself in the graveyard, but that seems so weird to me, because the last time it was on the field it would have forgot its effect. But than again i really don't understand why you can't reset it to begin with, except that it would be a rule built into the card. At the same time I could see how Skill Drain would treat the card differently than the other reset buttons.

it's a graveyard effect, so skill drain doesn't touch it. the second time it was in the graveyard the condition limiting it's use to once per duel would prevent it from being special summoned. flipping twin headed behemoth face down or anything like that doesn't matter. twin headed behemoth doesn't reset it's effect or "forget" that it's been used. it's once per duel has nothing to do with it being face up on the field so skill drain isn't negating anything while it's on the field. so it's not making the card "forget" that it's been used.

I guess that makes more sense. I was thinking that last part of its effect is a condition that exists while it's on the field. If it's negated before it's summoned than it wouldn't recognize the fact that it can't come back and would comeback or something. But, the effect always exists in the graveyard, so Twin - Headed Behemoth figures out how many times it has been on the field in the graveyard and only in the graveyard.

Basically, the second effect activates in the graveyard, keeping the first effect from activating again.

i should have checked netrep earlier, but this is the official ruling:

so like i said, it's a condition, not an effect. but at least there's something official to back it up.