There are two methods that would work, both require about the same amount of work:
Change all the warp portals to normal NPCs, with warp sprites (#45) and OnTouch labels. Warp players if (Upper != 8).
Add "Loadevent" mapflags inside all WOE castles. The next step depends on whether or not you have "loadevent" flags on other maps - if it's not too many, you could write something like this:
OnPCLoadMapEvent:
if (!agitcheck() && !agitcheck2()) end;
// Enable these lines if there are other "loadevent" maps
{
setarray .@maps$[0],"prontera","payon","etc.";
for (set .@i,0; .@i<getarraysize(.@maps$); set .@i,.@i+1)
if (strcharinfo(3)==.@maps$[.@i]) end;
}
if (Upper == 8) warp "SavePoint",0,0;