The last planegazer is the fourth of four bosses in the mysterious ornate quest. I team of 5 players need to kill the four bosses in 10 minutes, or they will be kicked from the boss room. There is no mechanic to kill them. Just kill. Some tips:
1- Reflection of a mage - Immune to fire and energy - Weak to physical - Strong to death (but you can use)
2-Reflection of mawhawk - Weak to holy
3-Reflection of obujos - Immune to earth - Weak to energy - Strong to fire, death and ice - He has mana drain
4-last planegazer - I do not find information about him, but me and my team just hit him.
More information about this quest can be find:
in english: https://tibia.fandom.com/wiki/Opticording_Sphere_Quest
In portugese: https://www.tibiawiki.com.br/wiki/Mysterious_Ornate_Chest_Quest