Shunga caption

[Pinus]

Hi guys, i have to draw a traditional-style shunga for my japanese art class at CSM and need some help with the caption: one should be like this:
"Miyamoto Musashi is surprised by his enemy during a sexual intercourse"
My hypothesis: 宮本武蔵は性交中に敵に驚かされる
The other one is: "He had to draw both swords quickly: which one will prove more deadly?"
My hypothesis: 彼は両方の剣を素早く引く必要がありました どちらがより致命的であることがわかりますか
Are they formally correct? Does they make any sense?
Thank you

 

[kanadaaa]

宮本武蔵は性交中に敵に驚かされる

宮本武蔵は(が？)性交中に敵に驚く

彼は両方の剣を素早く引く必要がありました どちらがより致命的であることがわかりますか

彼は両方の剣を素早く抜く必要がありました どちらがより敵に傷を与えられるでしょう (Which one will hurt the enemy more?)
The second half of your second sentence just doesn't sound natural.

I would go for the first one with:
宮本武蔵、性交渉中の敵襲 (Miyamoto Musashi, enemy attack during intercourse)

For the second with:
二太刀抜刀：敵に傷を与えるのはどちらの刀か (two swords pulled out: which one will hurt the enemy)
↑
ni-tachi or huta-tachi

 

[Pinus]

宮本武蔵は(が？)性交中に敵に驚く

彼は両方の剣を素早く抜く必要がありました どちらがより敵に傷を与えられるでしょう (Which one will hurt the enemy more?)
The second half of your second sentence just doesn't sound natural.

I would go for the first one with:
宮本武蔵、性交渉中の敵襲 (Miyamoto Musashi, enemy attack during intercourse)

For the second with:
二太刀抜刀：敵に傷を与えるのはどちらの刀か (two swords pulled out: which one will hurt the enemy)
↑
ni-tachi or huta-tachi

Thank you very much kanadaaa. I'm not sure about the second sentence, because it is actually a joke: the situation is that he has to stop the intercourse (so to pull out the first "sword"... i'm sure you understand) and to draw the actual sword to defend himself. So the meaning would be, in other words: with which one of the two "swords" (the true one and the metaphorical one) will he prove himself more valiant? Is your suggestion suited for this? Thank you again

 

[kanadaaa]

Ah, I didn't get that. Then maybe:

どちらの「カタナ」を抜くべきか (Which "sword" should he pull out)

In this case we don't need this part:

He had to draw both swords quickly: