Secret level , or not ?

[masterozof]

In book 5 there is supposed to be a secret level in which :
defeat clench
rescue 40 people from flood
watch prince galar escape
destroy neo arcadia base
however i'm not sure if I have the right secret level i think the level that you unlock by doing this stuff is the
dragon slayer arena ( something like the reward for defeating queen arcadia ) however i'm not sure I
have the right one can somebody confirm that this is the proper secret level for fufilling the above conditions .

P.S : i saw on the changes page that the conclusion of the Nekurow and Shizuka flashback is
available for those who completed the entire campaign . what does this mean i don't seem to get what
i means by conclusion to the fight ( They were cut off by sypha right ).

[RazorclawX]

Dragon Slayer arena is the level.

And yeah, Sypha interrupting the fight was the extended part of the scene. The original version the scene ended in the middle of the fight.