So Desert Temples are easy enough, right?
Rip open the hole in the wool, and either build a way down or just fall, and be sure not to activate the TNT under the pressure plates. Which is all well and good, if you like free stuff.
But some people want a challenge in their ancient temples.
"What about having randomly trapped chests, as well?"
What are you, a wuss? This is the time for ballsy suggestions!
Desert Temples need an optional Boss Battle to get the really good loot.
The Ruby Guardian lies in wait in a large chamber, about 40 blocks lower than the regular TNT/Pressure plate trap. The Temple would appear normally, with Wool covering the drop down to the "treasure room" but the chests would be empty, and also rigged to Sticky pistons that pull the very ground out from under you, causing you to fall the rest of the way down into the Ruby Guardian's chamber. There would be a pool of water at the bottom, so the fall can't kill you (Provided you managed to survive the fall into the fake treasure room in the first place.)
The walls would be made of smooth sandstone.
The room itself is a 21x21x6 chamber, with 8 Chiseled sandstone pillars at regular intervals, with torches on the 4 pillars, facing the middle. There are Blue and orange Wool patterns on the ground as well, which are mainly for decoration. There are 4 chests at the bases of each of the 4 pillars, with high tier loot, like enchanted books and weapons. Maybe even diamonds.
The Guardian would spawn on one of the 4 Orange Wool patterns, as soon as the player gets out of the water.
The Ruby Guardian:
The Ruby Guardian is a gigantic golden, snake-like automaton with a single, large, ruby eye and a long horn on its head.
Its body is comprised of segmented golden blocks, with various glowing lines and runes, that wiggle around while it moves. It is nearly indestructible, and can fire powerful lasers from its Eye to protect the treasures of the ancient civilization. It cannot be set on fire, nor can it be affected by Splash potions. It isn't even tricked by Potions of Invisibility.
It has 3 types of attacks, the First being a "Shot" fired from its head while standing up on the Orange Wool patches. These deal heavy projectile type damage, and create small Explosions on the ground when they hit, that launch the player a significant distance. The blasts are purely concussive, and do not destroy blocks. They can be avoided by sprinting away after the monster "Locks-on" before it fires.
The Second attack is a powerful Beam, that is fired at the player, while the Guardian leans down to about 2 blocks high to fire at level with the player's head. This does a lot of damage, but little knockback. There is about half a second before the beam is fired to allow the player to sprint out of the way.
The Third attack is automatic, touching the monster's tail or body does a small amount of damage and will knock you back a block or two.
It's large, glowing eye gem is its one weak point. Shooting it with a bow does a small amount of damage. Hitting it with a sword does adequate damage. Hitting it with a Pickaxe deals heavy damage.
Once the monster spawns, it will remain still for about 2 seconds, allowing the player to turn around, at least. It would then stand up tall and fire laser Shots from its head at the player's feet. While standing up it is out of reach from the player's Sword, meaning you would have to shoot it with a Bow to damage it. After it is damaged, or fires 3 shots, it would move to the one of the Blue Wool patterns on the ground, and begin firing Beams at your face. It is most vulnerable in this position, because its head is lowered enough for the player to strike the gem with a sword or pick. Hitting it with a sword does a good chunk of damage, but hitting it with a pick would do much more. However, it would also damage the pick's durability significantly.
Striking the Guardian, or allowing it to fire 3 Beams would make it move to the next Wool patch. It moves in a clockwise path from whichever patch it spawned on.
Once it gets down to 20% of its health, it becomes Enraged, and begins to fire Shots in 3-shot bursts, and its Beam in a sweeping arc, pausing only briefly after each attack and before moving.
When destroyed, it will freeze in place, the purple lines turning dark, as its body explodes, one block at a time, until it reaches its head, which will drop, then create a big explosion, dropping several levels worth of experience, several Gold Ingots, and a Desert Ruby.
You can use the Desert Ruby to craft a Beam block, and build a Beam Tower: Defensive emplacements that fire miniature versions of the Guardian's laser Shots at nearby mobs. Similar to one of my earlier ideas for Lightning Towers. While the Beacon is more of a Support block, acting as a way-point and providing AOE buffs, the Beam Tower would directly aid the player in combat, provided the combat is within the Tower's firing range. Beam Towers are crafted by creating a 3 block tower of Iron, Gold, Diamond, or Emerald blocks, and placing the Beam Block on top. The Tower can be built in any direction, as the Beam Block can be placed on walls and ceilings as well as floors, provided there are 3 Ore Blocks attached to its base. Each Block adds to the Weapon's power, range, or fire rate, giving you a bit of customization.
Iron Blocks provide no bonus, but are useful for filling in the Tower when you don't have other ore blocks.
Gold Blocks increase the range of the Tower by 1 block. (Standard is 8 blocks, maximum 11.)
Diamond Blocks reduce the fire rate of the Tower by half a second. (Standard is 1 shot every 2.5 seconds, Maximum of 1 shot every second.)
Emeralds Blocks increase the damage of the Tower by 1 heart (Standard is 3 Hearts, maximum is 6)
EDIT: You can also make the tower a block taller by putting a Redstone or Coal block at the bottom, which would change the pattern/style of the weapon, Redstone turning the Shot into a laser beam, while Coal turns it into a 3-shot spread fire pattern.
The Beam Block is crafted the same as a Beacon Block, but with the Desert Ruby in place of the Nether Star.
I like this idea it gives a nice offensive structure for you castles and the customisations sound really useful for different types of tower but it should be able to be disabled by mobs otherwise I can see it being overpowered.
It could burn out after a period of extensive firing?
Kinda like a redstone torch.
But then it would hardly resemble the weapon of the monster you got it from.
I think the idea of a boss battle in the temples is a good idea! As long as they aren't too difficult. The reason is because I think that the two difficult bosses should be the only bosses that are difficult. But a difficult mob, now I would agree with that.