deep dark city potential summoning/bossfight idea

the portal looking object in the centre of the deep dark city should act as a summoning oblisk for a boss or skulk infection or some cool loot item not a new dimension similar to how the old nether reacter used to work. a potential idea for activation should be activating all 4 redstone lamps around the portal and lighting a few candles in the frame which starts a cool summoning animation and when the bossfight is done the portal seals shut and for a few(minecraft) days the wardan becomes unsummonable(localized around the deep dark city where the boss was defeated(also the boss should drop some kind of loot different from the warden.