Demon Portal prevents end of combat if..

[onepiece]

But BD are inmune to enemy casted plague? If I remember correctly there's another spell that can also affect them but I don't remember which one is it.

[ckdamascus]

Because it is the Black Plague... har har. Get it? Black Plague?

Well it seems like the theme of this game with regards to dragons is they are weak against poison... so when they are revived, they are full of poison and resistance to such as Mr Bone Dragon.

[Jatekos]

Originally Posted by onepiece

But BD are inmune to enemy casted plague? If I remember correctly there's another spell that can also affect them but I don't remember which one is it.

Bowman's freezing affect them as well, causing serious loss of defense (and perhaps attack, but I'm not sure of it)