Talk:Frost Wall, Nevel Vans/@comment-36375292-20180827142512/@comment-26684750-20180827144724

FCBF Detailed Rules

See page 14, under 3.1.1. Destruction happens before the end of battle (and so does leaving the field), and everything in 3.1.1 is treated as happening simultaneously. This means that Astralkus is still not destroyed when Nevel Vans is being destroyed, and thus Nevel Vans can't be destroyed.

Continuous abilities are checked continuously (duh). Since another Asgard monster is not present, Nevel Vans will be destructible. If it was worded as an automatic ability like "When this card on your center is attacked, and you have another  monster on your field, this card cannot be destroyed by that attack.", then killing Astralkus in the middle of the attack would work, but it's not.