Oops, looks like I never replied back to this.
My proposed solution would be in perl.
Summary:
Invisible man controller spawns with 0 spider tokens.
Each time a spider is killed, it signals the controller. Controller increments spider token counter.
Once the controller has 20 spider tokens, spawn2 or unique_spawn whatever your boss npc id is and resets spider tokens to 0.
Code:
#invisible man controller
my $spidertoken = 0;
sub EVENT_SPAWN
{
$spidertoken = 0;
}
sub EVENT_SIGNAL
{
if ($spidertoken < 20)
{
$spidertoken++;
}
else
{
spawn2 whatever
$spidertoken = 0;
}
}
Code:
#spiders
sub EVENT_DEATH
{
quest::signalwith(controllernpcid,1,1);
}