$BOSS's arena has four $markings on the floor in the corners of the arena. Assuming the arena's entrance is on a wall and is not perfectly centered on the wall, markings are ordered like so:
$marking1 is in the corner of the entrance wall and the side wall closer to the entrance (thus it is closest to the entrance)
$marking2 is in the corner of the entrance wall and the side wall further from the entrance (second closest to the entrance assuming a squarish arena)
$marking3 is in the corner of the far wall and the side wall closer to the entrance (opposite corner from $marking2)
$marking4 is in the fourth corner. (opposite from $marking1, furthest from entrance.)
$markings[1-3] can include visual elements in their design to indicate they're numbered 1-3.
Boss
$BOSS is a big monster in the middle of the arena and attacks in melee. $BOSS has $moderate movement speed which is important as a balance factor.
Phase 1 (100-60% HP)
Upon hitting 90% HP, an $object spawns on $marking1. $BOSS will purge debuffs on itself, then try to walk to $object, and if successful, will consume the $object. This heals $BOSS for 5% of max HP and grants a $buff for 10 seconds which grants $some attack speed and 0.5% max HP regen per second.
$objects are attackable and have HP. They should be destroyed by heroes before $BOSS reaches them. $objects do not spawn again if consumed even if they cause $BOSS to heal past the %HP threshold. $markings disappear permanently once $objects spawn on them to indicate this.
Upon hitting 60% HP, an $object spawns on $marking2. $BOSS will purge debuffs on itself, become hasted to its normal movement speed (becoming immune to slows) for several seconds, then try to walk to $object. If successful, $BOSS will consume the $object. This heals $BOSS for 10% of max HP and grants a $buff for 15 seconds which grants $somemore attack speed and 1% max HP regen per second.
Phase 2 (60-30% HP)
Upon hitting 30% HP, an $object spawns on $marking3. $BOSS will purge debuffs on itself, become hasted to its normal movement speed (becoming immune to slows) and become spell immune for several seconds, then try to walk to $object. If successful, $BOSS will consume the $object, heal for 15% of max HP and gain a $buff for 20 seconds which grants $yetmore attack speed and 1% max HP regen per second.
Phase 3 (30-0% HP)
Upon hitting 0 HP, an $object spawns on $marking4. $BOSS becomes $ghostthing (becoming a different unit means the new unit has no buffs or debuffs) which is untargetable, invulnerable and will try to walk to $object, and if successful, will consume the $object. This resurrects $BOSS with 20% of max HP and a $buff lasting 25 seconds which grants $evenmore attack speed and 1% max HP regen per second.
The fight ends when the last $object is destroyed or the resurrected $BOSS dies.
As $marking4 is the only remaining $marking in this phase, heroes should really be prepared to position $BOSS far away from it in preparation.
Strategy
Killing $objects before $BOSS reaches them is optimal. Positioning $BOSS and heroes, especially nearing %HP thresholds, is very important. Experienced players can make use of the deterministic pattern/order of $object spawning.
Stand-in fluff
BOSS=Alchemist //(not Razzil, some demon that's a patron of alchemists, but his model can be used as a temporary one)
marking=circle of glyphs
object=cauldron
buff=definitely not chemical rage, totally
$BOSS
Arena
$BOSS's arena has four $markings on the floor in the corners of the arena. Assuming the arena's entrance is on a wall and is not perfectly centered on the wall, markings are ordered like so: $marking1 is in the corner of the entrance wall and the side wall closer to the entrance (thus it is closest to the entrance) $marking2 is in the corner of the entrance wall and the side wall further from the entrance (second closest to the entrance assuming a squarish arena) $marking3 is in the corner of the far wall and the side wall closer to the entrance (opposite corner from $marking2) $marking4 is in the fourth corner. (opposite from $marking1, furthest from entrance.)
$markings[1-3] can include visual elements in their design to indicate they're numbered 1-3.
Boss
$BOSS is a big monster in the middle of the arena and attacks in melee. $BOSS has $moderate movement speed which is important as a balance factor.
Phase 1 (100-60% HP)
Upon hitting 90% HP, an $object spawns on $marking1. $BOSS will purge debuffs on itself, then try to walk to $object, and if successful, will consume the $object. This heals $BOSS for 5% of max HP and grants a $buff for 10 seconds which grants $some attack speed and 0.5% max HP regen per second.
$objects are attackable and have HP. They should be destroyed by heroes before $BOSS reaches them. $objects do not spawn again if consumed even if they cause $BOSS to heal past the %HP threshold. $markings disappear permanently once $objects spawn on them to indicate this.
Upon hitting 60% HP, an $object spawns on $marking2. $BOSS will purge debuffs on itself, become hasted to its normal movement speed (becoming immune to slows) for several seconds, then try to walk to $object. If successful, $BOSS will consume the $object. This heals $BOSS for 10% of max HP and grants a $buff for 15 seconds which grants $somemore attack speed and 1% max HP regen per second.
Phase 2 (60-30% HP)
Upon hitting 30% HP, an $object spawns on $marking3. $BOSS will purge debuffs on itself, become hasted to its normal movement speed (becoming immune to slows) and become spell immune for several seconds, then try to walk to $object. If successful, $BOSS will consume the $object, heal for 15% of max HP and gain a $buff for 20 seconds which grants $yetmore attack speed and 1% max HP regen per second.
Phase 3 (30-0% HP)
Upon hitting 0 HP, an $object spawns on $marking4. $BOSS becomes $ghostthing (becoming a different unit means the new unit has no buffs or debuffs) which is untargetable, invulnerable and will try to walk to $object, and if successful, will consume the $object. This resurrects $BOSS with 20% of max HP and a $buff lasting 25 seconds which grants $evenmore attack speed and 1% max HP regen per second.
The fight ends when the last $object is destroyed or the resurrected $BOSS dies.
As $marking4 is the only remaining $marking in this phase, heroes should really be prepared to position $BOSS far away from it in preparation.
Strategy
Killing $objects before $BOSS reaches them is optimal. Positioning $BOSS and heroes, especially nearing %HP thresholds, is very important. Experienced players can make use of the deterministic pattern/order of $object spawning.
Stand-in fluff
BOSS=Alchemist //(not Razzil, some demon that's a patron of alchemists, but his model can be used as a temporary one) marking=circle of glyphs object=cauldron buff=definitely not chemical rage, totally
Stand-in values
moderate=280 //(movement speed) some=50 //(attack speed) somemore=80 yetmore=110 evenmore=150