Instead of simply recycling the roofs spawn code that seems to just rely on a % Chance any time damage is done to the boss I would suggest you use more of a system similar to the travesty.
Make the bosses Spawn monsters at certain HP Intervals with a decently scaled Cool down timer in between to prevent multi pops, Scale the # of mobs to the # of players in its enmity list, And control which mobs spawn at which hp intervals to make the fights more challenging at the end. This will Create a "Burn Add" Phase or a dps check for groups before they can return to the boss and damage it down in the time limit to prevent respawn. This will give the fight a unique, but consistent feel on top of the bosses random Cast/attack AI.
@Kyronix @Bleak
Make the bosses Spawn monsters at certain HP Intervals with a decently scaled Cool down timer in between to prevent multi pops, Scale the # of mobs to the # of players in its enmity list, And control which mobs spawn at which hp intervals to make the fights more challenging at the end. This will Create a "Burn Add" Phase or a dps check for groups before they can return to the boss and damage it down in the time limit to prevent respawn. This will give the fight a unique, but consistent feel on top of the bosses random Cast/attack AI.
@Kyronix @Bleak