The mechanism of respawn is difficult to recognize when we talking about such rare bosses. So far, none of the fansites have published information about this mechanism. Several theories have been formed among the bosshunters community about the spawn of these bosses. One of them turned out to be true. After many hours of research, I finally managed to solve this puzzle.
During one of my researches, I assumed that the respawn of the boss could be shared with another monster. You can read more about this spawn type on the Tibia Wiki. I went to the place where Burster was seen by the players (Marked on the screenshot below).
Due to the fact that the bosses spawn time is extended twice, I started to check every possible spawn spot of the monster In this area. I figured out that one spawning spot is extended in time. It is exactly the place marked on the picture below.
I started to regularly kill Instable Breach Broods appearing in this place. After a few hours of the killing, the Burster finally appeared before my eyes. He spawn in the marked place so the theory of shared spawn proved to be true. What's important is that we can trigger the boss to appear by killing the monsters from this spot. With each kill, we have a chance that the next monster to appear will be Burster.
What about the Dreadful Disruptor? Of course, I went to the place where the boss was seen (Marked on the screenshot below).
I started killing monsters in the marked place. After some time the boss appeared. I didn't find the exact spot, but the respawn of Dreadful Disruptor is in the middle of the marked area. Surely the same mechanism is responsible for his respawn.
Both Dreadful Disruptor and Burster can appear more than once per day. As proof, I attach a screenshot of Dreadful Disruptor kill statistics taken from guildstats.eu
This also provides hard proof of the shared spawn theory. Because this type of respawn allows you to meet more than one boss a day.
So The final answer is:
The Spawn mechanism of Burster and Dreadful Disruptor is the Shared Spawn mechanism. To trigger the boss spawn you have to kill the monster in a certain spot. Every time you kill the regular monster, there is a chance that the next monster that appears will be the boss.
• It's hard to meet these bosses. Usually, many hours of tries are needed to first spawn
• I have never met a boss twice in one day. This must happen extremely rarely.
• Dreadful Disruptor is a strong boss. In my experience, he is stronger than Zushuka or Tyrn.
• During the fight against the Burster Or Dreadful Disruptor you can go downstairs. There are no monsters in the underground area, so you can easily refill the mana and HP there.
Varying Monster Spawn | TibiaWiki | Fandom
Where can I find bosses from The Void - Burster and Dreadful Disruptor? - TibiaQA
Dreadful Disruptor kill Statistics - GuildStats.eu
Burster kill Statistics - GuildStats.eu