Add Tombstone to Minibosses
Description
As title says, I suggest the implementation of tombstones (like those MVPs have) for minibosses.
Rationale
I've been hunting Angeling, Deviling and Ghostring frequently in the last couple weeks and I've seen how easy it is to completely monopolize these monsters. If you have the timers and you are diligent about it, you can go on long streaks of kills. On the other side, it sucks so much when you don't have the timers: you have to constantly check the maps and teleport for long periods of time without knowing if you're within a spawn window or if someone just killed them. With or without timers, it sucks to have to teleport without rest for up to 30 minutes when the spawn window begins to maximize the chance of finding the monster before anyone else. I've seen some discussion about this matter on issue #1300, but it is still open and there is no clear staff position on it.
As I see it, adding tombstones for minibosses would be extremely beneficial. Currently monopolizing is simple but boring and trying to break it and compete is utterly uninteresting. By adding the tombstones there will be more space for competition, in the exact same way, I believe, it happens with MVPs. Besides leveling the playing field, the tombstones will also remove the need to constantly teleport in rapid succession during the spawn window, this being replaced by the equally boring but less strenuous activity of staring at the tombstone until it vanishes.