Skimming the forums, I saw a lot of people were having trouble with the No Lasers! achievement. I was included in that number, until a friend and I found a way to easily get it. So, starting off: some basic info about the specifics of the achiev.
1. If a laser hits anyone, you have to leave the fractal entirely and come back. GG'ing won't work.
2. If you're fast, the person being targeted can GG before the laser strikes. The other player(s) can then also gg to reset everyone, and since technically none have been hit by a laser, leaving the instance is not necessary. (this is a good way to save yourself if you're stranded nowhere near a shield crystal and you know it's gonna get you.)
3. The laser CAN be evaded
4. The laser CAN NOT be blocked
5. Killing a tentacle or a jade collosus spawns 1 shield crystal
6. Jade collosi will reflect projectiles UNLESS they have already been engaged in combat (by a pet/minion aggro, some sort of non-projectile pull, another player, etc.)
7. Take a LOT of stun breaks/speedups.
8. When a laser hits your crystal and gives it a charge, you don't HAVE to throw it. Holding onto it or dropping it will retain the crystal.
So, onto what we dubbed the "Crystal Garden" method. (We were a DPS soulbeast duo on voice chat for this; the more people you have helping you, the more complicated it will become to coordinate sharing the crystals, but voice chat is not necessary for this method as long as everyone has patience and doesn't greed.)
Fight starts; wipe out the irukandji first, and the 2 back tentacles last. Once the last one is down, retreat to the far end of the space from the jade maw- it'll give you some breathing room. The very beginning is somewhat luck- a reflecting crystal/collosi may spawn right near you, in which case, hell yeah. Whoever gets the skull, grab a crystal and retreat back to that starting point where the tentacles won't knock you down. DON'T THROW IT. Just hang onto it, while the other person(s) deals with the nearest tentacle and/or jade collosi. If the skull targets you again, great; keep holding onto that crystal like a champ. If it targets your partner, assuming they don't have a crystal themselves, DROP YOURS for them. Also do not have them throw it- have them hold it, because now it's your turn to pull and kill some jade collosi. Repeat this process- absorbing the laser and taking turns getting crystals from the adds- until you are both able to each hold 1 crystal in your arms, and have at least 3 spares on the ground right near you. You can then take turns throwing charged crystals (or designate one person to be the thrower) and constantly keeping a supply of 3+ spares on hand.
Unless you get unlucky with add cc or other small mistakes, the Crystal Garden is a very safe way to get the cheevo. We'd failed over a dozen times, then got it on the first attempt by doing it this way. Let me know if you have any questions, and good luck!