User blog comment:B214/Volume 21 info & spoilers/@comment-26510794-20160331201613/@comment-202.183.235.8-20160401003604

Depending on how the seal work (although I believe that continuous fight is unlikely).

1. it may put Sirzech and the others in coma state and they would awake when unseal.

2.  it may put Sirzech and the others in coma state and they would die when unseal.

3. it may destroy a body of  Sirzech and the others and seal their spirit along side Trihexa (similar to a case of Ddraig  and Albion)

Personally, I prefer to have them died for real since it would make more impact than they survive.