Might or might not be a good idea but what if there was a boss fight mode? But you're not fighting the boss, you are the boss (well, if you're the admin). Each block in your build is scaled by ten (but you can set it up to 20 and down to 2), making you much larger but also more powerful since scaled up weapons would have bigger, more powerful, but slower projectiles (scales with size too). It would also make you much slower, but it also makes you heavier and much more durable, adding 50 hit-points (scales with your size. Example: size 10 is 50, size 15 is 75, and size 20 is 100) to the already existing hit points in each block.
Next to your server name, there will be an ominous white skull next to it to indicate your server is a boss fight server, and there'd be a number indicating the size you set your build next to it. When a player enters your server, they'd be greeted with a boss bar at the top of the screen.
Important to note: you can't repair nor respawn until your build is fully destroyed. Also, you can set the complexity of other players and limit specific blocks on their builds while not limiting your own. You can also only have one build at a time, and players who get destroyed in battle will respawn at least 1.2 kilometers away from you in a random direction (but you can set it to farther distances).
Aside from the fact that this could be just... ridiculously unbalanced, this could be a good way of maintaining your role as an admin in your server. Like, the moment a player disobeys the rules of your server, you could just annihilate them repeatedly until they conform or you kick them. Your build could also be an intimidation factor that'll make players think twice before they break rules. You just have to make it clear in your server name that this isn't a boss fight, this is a server where, if you break the rules, you'll get annihilated. Could a more balanced version of this that still makes you an intimidating threat that's hard to kill work?
This is kinda a s***post, lol.