When you fight the Basilisk & lose, it says you are killed, does that mean you are dead & if able draw another character.

alboy said:

If the Basilisk rolls doubles with both die's, then you are killed ( instant death)

If not, and you lose, then you only lose 1 life ( as normal)

Yes, you need to draw another charactrer then

can you prevent this death with spells like preservation?

ososober said:

IIRC, those spells only prevent the loss of life after losing in combat, Basilisk doesn't make you lose lives, it kills you outright. So no.