<p>If you plan to complete this bestiary, bosstiary, you can only enter one boss per Stage 3.<br>There are three bosses but since you need to open their chest to reenter each lair and you can only open a chest each time, you can effectively enter only once per Stage 3.<br><br>The Stage 3 lasts for 5 days, with a 1 day of Stage 2 that makes it 6 days total. That would make it 300*3*6 = 5400 days or close to 15 years as a maximum.</p><p>But that is a maximum value. <strong>There is a trick to it:</strong><br>Once entering the lair of one of the bosses, players have 20 minutes to be in there. The bosses respawn in 5 to 10 minutes time, so if you take a stronger team you can kill them multiple times.</p><p>Additionally, the entry to the lair is only denied after gaining experience from the Boss, so players can leave and reenter when at very low HP to gain time.<br>Effectively, with a good enough team you can kill the bosses at least 3 times in that timeframe. This would bring the 5400 days down to 1800 days, but I believe 4 times is achievable if the spawn rate of the server is good enough.</p><p>Without testing, I assume the respawn rate is also affected by rapid respawn (global or area) enough.</p><p>Rapid Respawn events so you might sneak in more kills there.</p><p>300 and increased respawn areas do not affect boss respawn timers.</p><p>300 kills is a lot for them, but given this respawn mechanism 60 could be too low compared to others.</p>