You Know How to Reach Me

This achivement is such a snoozefest. Firstly the zone is really poorly designed. One can see treasures on the minimap and as soon as one gets close one is suddenly on a completely different shard. The respawn rate on the treasures is mad poor. Also the way the achivements are structured are totally made by a griefer. First you see you only need 10 scrolls which seems fine and doable, similir with 25 treasures, you reach it just to realize you need 50 scrolls and 100 treasures. Complete garbage and I really hope Blizzard doesn't implement anything similar in War Within. Alot of the other achivements for the Dragonflight meta achivement you progress towards through regular gameplay but here one gotta go out of his way to reach completion.

Sorry for being so pessimistic just needed to rant. Only need Morqut provisions and 25 more scrolls now and then I'm never setting foot in this horrible zone again.

Doable in a few days of not touching grass. The longest part was the treasure scrolls, my advice is to save up elemental dust and buy a bunch of the blue "increase your chances to find treasure scrolls" and then join a group farming under the mountain for BoA drops. Got about 30 in 4-5 hours.

Useful things to do to prepare for these achievements:

ACQUIRE SUPPLIES
(1) Have a ton of elemental overflow and dragon isles supplies. If you've already been Taivan hunting, you'll have more than you know what to do with.
(2) Buy all the profession items needed to summon the rares. Check comments on Champion of the Forbidden Reach to find a useful list.
(3) Go to Morqut Isle and find the envoys. Buy the following:
- [item=204481] (Tuskaar guy). You can only carry one, but it has 5 charges. It's helpful to get back quickly for more supplies.
- A ton of [item=202196] (any vendor). Check the comments on Every Door, Everywhere, All At Once to see how many keys you need in total.
- a few [item=204558] (Dragonscale dwarf). You can carry multiple at a time, but they do not stack.
- Lots of [item=204560] (Drakkonid guy). You can carry multiple, but they do not stack. If you're extremely unlucky, you may need one for every scroll you're missing for Scroll Hunter, but you don't have to buy all of them at once (or you will run out of space and/or elemental overflow).
- [item=204559] (Centaur). You can only hold one at a time.
(4) Choose whether you want to go for the vault related achieves or the rares and treasures first. You can try going for rares and treasures to save resources on buying keys, but it's slow, and you probably have a bajillion supplies anyways.

VAULT:
(1) Take all your keys and open all the vault doors on one character. Check all the rooms for:
(a) any scrolls or books that need to be picked up for Librarian of the Reach or While We Were Sleeping (some items spawn specifically in the vault).
(b) If the bubble machine is present, look for [object=386573], which contains [item=203690], allowing you to use the machine and swim (yes, swim) further up into the vault
(c) [object=385687] (usually on second level), which lets you jump to the next platform. You can also use the jet pack instead of the flask, but I find it more difficult to control.
(d) Any cool shinies (like toys) that you want to get from the vault.
(2) Send leftover keys to an alt. Open as many doors as possible. Again, check for missing lore objects. ALTERNATIVELY: Wait another week to do it on character 1 again.
(3) Repeat step 2 as many times as needed, buying/obtaining more keys if needed.
Useful tips:
- You will have to complete the quest chain that starts with Helping Hand and Claw to unlock the vault; you have to complete it for every alt that you want to use for Zserka vaults, but it shouldn't take long.
- It helps if at least one of the characters doing the vault is a demon hunter or evoker, they can jump to the next platform without using items, allowing you to skip looking for [object=385687]

RARES:
(1) Use the [item=204559] - it lets you see nearby rares and spawners on your mini map (it also lets you see the treasure goblin). May as well use [item=204560] in case a rare drops a scroll.
(2) I recommend getting all the profession rares out of the way first. Use the comments under Champion of the Forbidden Reach if you're having trouble finding them. Bring a buddy or two to help them get the achieve too; and make sure everybody has tagged it first before killing, these guys don't have much health.
(3) The rest of the rares will spawn naturally and show up on your main map. Go around and do your normal thing in the Reach.
(4) If you happen to find a [item=202667], you'll have to use another [item=204560]

TREASURES:
(1) Use the [item=204558]. Use the [item=204560] as well.
(2) Fly around looking for treasure. Comments under Treasures of the Forbidden Reach, can help you with common spawn locations for random treasures.
(3) If you happen to find a [item=202667], you'll have to use another [item=204560]
(4) Keep an eye out for forbidden hoards and the items from Librarian of the Reach and While We Were Sleeping.
Useful tip: make sure to check all the nooks and crannies, caves, towers, buildings, etc. Sometimes lore objects are in there!

SCROLL HUNTER
Scroll Hunter is by far the most time consuming, expensive, and RNG heavy achievement, thus earning its own section. Make sure you have a ton of [item=204560] in your inventory, and a [item=204481] to go back for more crystals.
(1) Go to Froststone Vault and camp inside. If there are no others there, invite a group to speed the scroll farming up. Or join a group.
(2) Talent so that you can AOE farm, and have the buff from [item=204560] active at all times.
(3) Murder.
(4) Once you have a big pile of corpses, loot them. If you're lucky, you'll have multiple scrolls picked up at once. Or you could be extremely unlucky and get nothing.
(5) If you picked up any scrolls at all, the buff from the crystal has now been consumed. Use another [item=204560].
(6) Repeat steps 3-5 until you either (a) run out of crystals, or (b) get all the scrolls you need. DO NOT OPEN ANY OF THE SCROLLS YET. KEEP READING FOR HOW TO DEAL WITH THEM.
(a) if you've run out of crystals and still need more scrolls, use the [item=204481] to go back and buy more. Then go back to step 1 to farm some more.
(b) If you have all the scrolls you need? Good. You can leave the vault. Read on to find out how many scrolls to open.
(7) Thanks to Nasenbaea and SerroDan on the comments for Scroll Hunter, we know exactly how many of each scroll we can open before all the treasure spawns are used up: roughly 5 of each type. You will have 4 types of scrolls, open 5 of each. You will get a warning if you can't open any more.
(8) Go to one of the x's on your map, and pick it up. I find that spam clicking does not count towards the achievement, don't bother with that. Don't leave the spot yet.
(9) Open another scroll of the type that spawned that x (so if you picked up a fish, use a fish scroll). Pick it up. Repeat this step until your scrolls of that type are used up.
(10) Go to another x and repeat steps 8 and 9. Etc.

OTHER TAIVAN ACHIEVEMENTS HERE:
-You may as well finish off all the races for Forbidden Reach Racing Completionist while you're on the Forbidden Reach, so that you don't have to come back here.
-You also have to wait for specific times to complete Under the Weather, so if you're close to a spawn time, head to that area and wait.