I would be a strange boss.
I would tell a story about where "There would once be an old hermit considered a madman because of a routine he did daily, go into his garden, pluck a turnip and carry it to the woods where it would be dumped into a lake. For ages, the villagers though he was throwing away good food that his son thought he was out of his state of mind due to his age. The day came where the old man begged his son to carry on this insane tasks on his death bed, where he then passed on. His son never followed through." I would turn towards the protagonist and my eyes would twitch. "It was until about no less than a day, creatures from the forest erupted. Strange ones that consumed homes, livestock and even humans. It wasn't until the son fell back to his father's farm he discovered those creatures had avoided him and the turnip patch... It was then discovered that the turnips being grown we're used to keep the creatures away from his village... Though the information came at a time of naught for that the village had been consumed by the Eldritch beings. The only one who was standing in their way was someone who was deemed unhealthy, out of his state of mind, insane." I would draw my weapon, a spear made of some strange breakable glass, that was able to cut into the floor like butter. "The funny thing about that story, the reason I established my guild? I didn't do this to conquer the world, I didn't do this for power. For all I cared, the glory of power, conquest and women could rot and decay where it stood and my guild mates could chase their ideals until their well met ends where their greed would lead them. No; the reason I did this was because I was the son in that mad tale, I did all of this to protect and fight for what was left here at home... Well, that matters little now. Who will walk away from this and who wouldn't, I won't know... But at least promise me you won't hold back child and do not back away from what comes next."
I would have 3 phases. First phase would be a hard to fight warrior with heavy shield and a glass spear. No crazed weak points or moments to strike, the player would have to fight a hard battle and risk losing hp constantly to get past the first phase, using their brain to fight and keep alive. The second phase, I'd toss my main weapon and use my shield as my next weapon to bash and stun the player, use it's edge like a boomerang to cleave through armor while using my fists once the shield is gone.
My last form, I would shed the combat armor and weapons and start teleporting around the battle arena, using energy blasts, energy spears, using gravity and the battlefield to my advantage, creating 1-hit kill blackholes and destructive tactics to rip open holes in the ground for destructive pitfalls.
Once my last form is beaten, would lay on the battle field still grasping to life to allow the player to make a choice, finish me off, walk away and leave me for dead, or heal me for what comes next... My Last words would be as to finish the story; "The son sought out the survivors of his village, and began a conquest of duty to seek those creatures out to ensure they do not bring harm to anyone else. Even if it meant to loose themselves in the process."
Game design is one of my big passions; I've had time to think about this a looooooooooooooooooooooooooooooooooot.
