Prismatic Trials with the Engineer

Are you ready to get BUSTED speeds with RANDOM, RANKED SEEDS? Read this hot garbage, and beat your friends!

Basics: The Engineer.

For starters, you'll need to unlock the engineer. Not super hard, you need to complete 30 levels overall. This can be done on drizzle, but it's probably better to do it on rainstorm just to get practice with the difficulty type, as all prismatic trials so far have been on rainstorm, and may possibly be on monsoon later on.

Nothing else needs to be unlocked, however. All items within the item pool are spawned without needing to unlock them first, so a general familiarity with items is all you'll need past this point.

The Items: What you need.

Now, so far, all prismatic trials involve 2 steps: Destroying 3 Time Crystals and then activating the teleporter. Unlike the base game, killing the boss before the teleporter charges will automatically finish the teleporter charge. This means you want items that boost your DAMAGE, or keep you alive long enough that all you need to do is FOCUS on damage.

BUSTLING FUNGUS
Wait, you just said you need items that deal damage. Well, this is BY FAR one the BEST healing items in the game, especially for the engineer. See, your turrets (Activated on R) act as copies of your items with a medium speed gun turret. This means that as they cannot move, they will ALWAYS form a healing field around themselves, and can serve as healing stations for yourself, as WELL AS allowing them to heal EACHOTHER. This means they will ALWAYS BE UP, and ALWAYS DEALING DAMAGE. This does mean, however, that your turrets should ALWAYS be placed as close to the boss as possible, as the boss spawn will always be in the same static position.

ARMOR-PIERCING ROUNDS
These things SHREAD bosses, even in the base game. It's a free extra percent of damage going to the only place where your damage needs to go, right to the boss. It also affects your turrets as well, but your turrets get easily distracted by fliers and minions, so don't always expect them to be doing much unless they're RIGHT on top of the boss.

TRI TIP DAGGER
Not nearly as good as other items, but the bleed chance on your turret hits will allow for you to keep up more consistant damage on your targets as much as possible. If the trial is long enough to allow you to get 7 in one run, every hit will apply a full stack of bleed, meaning your basic attack will start dealing SIGNIFICANTLY more damage over time, especially when charging a volley. Having more than 7 does not make the effect more effective on most characters, including the engineer.

ENERGY DRINK
Depends on the map, but if you're on a larger map, this can make all the difference as to if it's worth getting certain further items for your build. Same thing applies to Paul's Goat Hoof, but the sprint bonus is more beneficial overall since you're not going to have many times when you're sitting down and fighting, especially considering how much money time crystals grant you.

Fuel Cell
Risky but potentially run-making item right here. If you have a damaging active item, or an active with a low cooldown, this can absolutely SHRED certain bosses. However, it's by no means necessary, and getting both the cell and the active are both time-investments in each run.

Red Whip
OH YEAH WHENEVER YOU CAN. Considering that you're going to be out of combat as much as possible, this allows you to get otherwise risky items based on the time investment worth it. Not effective during the boss fights, but otherwise a runmaking item, especially if the teleporter is far off. Remember, the Engineer is SLOW. Anything that is a SIGNIFICANT movement speed bonus is always a plus.

Wax Quail
See above. Makes more vertical maps MUCH easier to traverse, and is typically faster than double jumping if available. If it's on the way, grab it if you can.

MOST/ANY RED ITEMS
Honestly, most all of these items increase damage, or allow you to heal much more effectively. Take these if at all possible, but keep in mind that some (Dio's Best Friend, 57 Leaf Clover, Brainstalks) are significantly better for the long run, not your speed run.

Viable Actives
Your choices here, in order from best to worst are: Preon Accumulator, Occular HUD, The Backup, Disposable Missile Launcher, and Glowing Meteorite. These will either shread your boss, or consistently allow you to deal much more damage to the boss and nearby minions. In particular, Preon Accumulator can oftentimes just one-hit the boss on earlier waves.

The Abillities: What to use and when.

M1: Grenade Launcher. Good damage, especially when held down. I honestly haven't done the math and recorded the data, but more often than not hold up and charge all your shots just to make sure you can hit the boss or any larger enemies in your way. Also good for taking out the last few hits of a Time Crystal's Health, but do NOT use it for the whole thing if you can help it. It's just too slow most of the time.

M2: Landmines. You can at base hold 10 mines, and on the first map it takes 5 mines to break one Time Crystal if you toss the mine RIGHT onto the crystal. You can also sometimes get away with 4 miens and a single M1, if you're lucky. Not only should you use these on crystals for faster clearing, but use these on the boss's initial spawn point to start him off as low as possible.

Shift: Forcefield Bubble. Your first temption when you start the boss fight is to drop the shield, but hold off on it until you KNOW the boss is targeting you. This will allow you to block the Titan's Laser beam, the queen's acid volleys, the Clay pot's bomb volley, Imp Overlord's needles, etc. etc. Try to use it only in response to actual threats, because of how long the cooldown on it is. Also, remember that your shield is LOBBED where you aim! Tossing your shield off into the distance can cost you the run if you're not thinking.

R: Turrets. The BREAD and BUTTER. These are your farmers, tanks, and healing dispensers all in one, dependent on your build. Try to keep them alive if possible, but don't be afraid to spawn one closer to the boss as a sacrificial lamb if the boss's damage is getting too aggressive. Drop them by the edges of your forcefields if you can. Use often and use agressively.

Other Details: (4/5/19)

• On every prismatic trial, run it with a more mobile character like huntress, MUL-T first just to figure out where certain spawns are as the Engineer's items in Prismatic Trials are very VERY niche to do well.
  
  
• That being said, test runs should be low and slow to as best as possible map out item spawns, as well as possible timed chests/altars/achivements.
  
  
• You can TOTALLY use prismatic trials to cheese out achivements, since you know the boss ahead of time and can retry with the same items if you desire.
  
  
• Lunar items are risky to use on Prismatic trial, as often times the benefit is only good in the long-term or the cost will be way too high. Then again, Shaped Glass can be a complete run saver, just make sure that you've got a good stock of Lunar Coins.
  
  
• Don't be afraid to get a few items more than you think you'll need until you're confortable beating the boss without them. Whittle down your builds with each go until you find items you think you can live without, and keep going with different combinations to see which nets you a better time.

I'll update this guide as more content is added to the game. But probably not.

But maybe.

[Zeddy]

I'm more of a casual runner, but I feel like I have advice to add here. My best run so far looks like this:
https://www.youtube.com/watch?v=D2bwyoyZla8

My preferred way to crystals is to approach them with a grenade launcher load (start charging, sprint up close, get the whole load in) from just the right distance, then finish off with 2-3 mines. The important bit about the mines is that they have delayed effect, so you can position yourself just right so that the crystal explosion sends you boosting.

I don't think I'd ever go out of the way for a Fungus, trials are just too short, so turrets are fairly immortal as is. The important part for fast boss clears with engie is getting a usable, and if not just be really good with mines and 'nade launcher.

A real speedrunner probably would have more intricate advice to give you.

Don't forget that you can place mines on bubble shield, allowing mines to hit things like Vagrant and Imp.