Everyone wants to have strong weapons but strong and flashy weapons? That's the domain of the Mage class. Magic weapons tend to be the most impressive-looking weapons in Terraria and have an incredible potential to do massive damage. But, of course, none are more impressive than the ultimate Mage tool, the Last Prism. This post-Moon Lord death ray harnesses your magical power into an unstoppable destructive beam that is only beaten in damage potential by the newly added Zenith.
Obtaining the Last Prism is just one simple step: defeat Moon Lord. It drops from him about 10% of the time so it might take a few tries but it is really as simple as that. Though calling fighting the Moon Lord simple may be a bit too hasty.
Being the final boss of Terraria he’s gonna put up a fight, so you’ll need to be prepared. If you’re having trouble dodging his attacks try using the Soaring Insignia dropped from the Empress of Light boss to gain infinite wing flight. Or alternatively you can make a long stretch of asphalt to increase your speed and outrun the Moon Lord.
However you choose to do it, Moon Lord has to die before he bequeaths you with this final magical prize.
The Last Prism is a unique magic weapon to use. To reach its full potential, you must keep the attack button held down for a few seconds. During this time a number of small beams will be emitted from the Prism, which converge on each other and eventually turn into one giant beam that does incredible amounts of damage.
When it's fully focused, it will drain your mana very quickly but it will also shred enemies, turning them into nothing but a pile of gore effects and leftover damage numbers in the hundreds.
You can aim the weapon wherever you want but it does take some time to catch up to your cursor. But during this time it will sweep across the screen smoothly and decimate anything it lands on so a slow sweep is excellent for taking out crowds.
As powerful as it is, the Last Prism can be hard to use. With its cumbersome chargeup and 72 mana per second cost when fully charged, using this weapon can take some preparation. The first thing to fix is the mana cost. There are a few ways to go about this, one is to simply stop firing to regenerate your mana but that causes the charge to be lost. Instead, the Last Prism is best paired with a Mana Flower and Super Mana Potions, or with Magic Cuffs. These items combined will help refill your mana bar and keep the Last Prism firing for longer.
The Mana Flower can be crafted at a Tinkerer’s Workshop with a Nature’s Gift found growing in the Jungle biome, and one Mana Potion crafted with two Lesser Mana Potions and a Glowing Mushroom.
Super Mana Potions can be crafted at a Bottle or Alchemy Table with 15 Greater Mana Potions bought from the Wizard NPC, 1 Fallen Star collected at night, 3 Crystal Shards mined from the walls of Underground Hallow caves, and 1 Unicorn Horn dropped from Unicorns in the Hallow biome.
The Magic Cuffs can be crafted at a Tinkerer’s Workshop with a Mana Regeneration Band made by combining a Band of Regeneration and a Band of Starpower, and a Shackle dropped by Zombies.
If you simply want to use less mana and don’t mind the Prism being unfocused, quickly hold and release the attack button and only ever fire the focusing state. This state costs less mana and is still effective in taking out large groups. Though it is less effective on single targets like bosses.
The Last Prism is a late-game magic weapon that drops from Moon Lord and can decimate both single targets and groups. Though it does take some work to get, you’ll have to farm Moon Lord a bit, it's well worth it as it's the second most powerful weapon in Terraria. Though it does use mana very quickly so be sure to have a setup that's ready to refill mana very fast.
Strangely, yes and no. The Spectre Armor’s healing ability works with the Last Prism but only during its focusing phase. Once the beam is fully focused, the healing will stop, so if you want lots of healing go for the strategy of keeping the weapon in its focusing phase all the time.
Due to the fairly low drop chance, it's unfortunately, a high number. The average I got was about 8-9 kills between him dropping the Last Prism. Though, as long as you have good mobility you can learn the fight and become more consistent as you go. And the more you kill Moon Lord the more Luminite you get which is good for crafting your endgame armors.