Changes: Removing the Darkness From Within...

You need 50k faction with Teren's Grasp. 40k with Synod Reet. 50k with Clan Skleross
You need to have completed the heritage quest Casualties of the War of the Fay and need to have the Raincaller in your inventory for part of this line.
You need to speak the Froak language. (A Mysterious Green Tome Collection)

Steps

Talk to Allysha Lanne in South Qeynos located on the second floor of The Herb Jar on Lucie Street. ( 649, -13, 240 ) Copy/waypoint 649, -13, 240 .
Speak to Robylie Sewnadel in the The Enchanted Lands in The Glittering Mine. ( -69, -2, -1088 ) Copy/waypoint -68.5, -1.5, -1088
Recover Robylie's Triocular Magiscope from a vampire den in the Loping Plains. It is in the single room by the jail area in Castle Mistmoore. ( -251, 5, -6 ) Copy/waypoint -250.77, 4.90, -5.90
Return to Robylie Sewnadel in the Enchanted Lands in The Glittering Mine.
Head to Sebilis and kill Iksar for osmotic stones updates.
Head to to the Laboratory in Sebilis for the Reticulated Damagifier. ( -317, -22, 331 ) Copy/waypoint -317, -22, 331
Head to Teren's Grasp and talk to Dondal Sewnadel ( 2246, 524, -968 ) Copy/waypoint 2246, 524, -968 for next update. (This step requires 50k faction with Teren's Grasp)
Head to the Highton to speak to Robylie Sewnadel again near the Highton sokokar post.
Walk along the Gash of Thelin on the Karatun Hold side of the canyon till you get an update to track a wounded animal. ( 1239, 138, -2382 ) Copy/waypoint 1239, 138, -2382 Track for a blood splattered rock ( 1164, 138, -2468 ) Copy/waypoint 1164, 138, -2468, inspect it when you get to it. Track for a broken branch ( 974, 163, -2476 ) Copy/waypoint 974, 163, -2476 and inspect it when you get to it. It leads you to a deer to the eastern mountain wall ( 847, 222, -2547 ) Copy/waypoint 847, 222, -2547. Examining the deer corpse will spawn Enraged Wumpus. He is lvl 85 ^^^ and casts knockback for 5k+ damage every so often, his KB also does a stun for about 5 secs or so in duration. Loot the chest that the Enraged Wumpus drops for a darkened arrow head. You'll have to do this for each Ranger in your group.
- This is an auto update now .. all Rangers on this step will be updated.
Go to Fens of Nathsar. Start by finding a trail ( -556, -112, 1480 ) Copy/waypoint -556, -112, 1480, follow clues (Bloody Bones ( -755, -107, 1493 ) Copy/waypoint -755, -107, 1493 and "a water hole" ( -755, -146, 1320 ) Copy/waypoint -755, -146, 1320) to ( -858, -120, 1240 ) Copy/waypoint -858, -120, 1240. There is a froglok corpse there: Click it and an Enraged Razorfang will spawn. He fears, but can be duo'd or trio'd with a Ranger or with ranged classes. This monster has about 450k to 460K HP, a duo is recommended.
You need to head to Kunzar Jungle, search around the poacher camp for an auto update ( -431, 22, 21 ) Copy/waypoint -431, 22, 21 similar to the ones before. You need to find and examine a campfire ( -613, 19, -99 ) Copy/waypoint -613, 19, -99 and a horse ( -415, 23, -173 ) Copy/waypoint -415, 23, -173. Investigate the tent ( -525, 43, -180 ) Copy/waypoint -525, 43, -180 and an Enraged Poacher spawns. This is near Hunter Snake-Eye ( -455, 42, -199 ) Copy/waypoint -455, 42, -199).
Return to Robylie Sewnadel near Highton sokokar post.
Robylie Sewnadel will tell you to seek out a Ranger named Ryvenar Sal'Vara. Go to the Skleross Encampment in Jarsath Wastes. You MUST have Raincaller in your inventory as well as 50k Clan Skleross Faction to get this update.
Ryvenar Sal'Vara will send you to find a Fungus called Delupore. Go to Chelsith and clear to where the mucous named is. Fulgothom the Ichorous, an 85 ^^^ will spawn when you get close. Kill Fulgothom the Ichorous and Delupore will spawn as a harvestable mushroom for your update.
Head to Kunzar Jungle to the Reet Camp, speak to Fisherman Quurp to get the other Fungus Sample (40,000 Faction with Reets is needed) and you need to speak Froak. May need to do the sub quests starting with collection A Mysterious Green Tome.
Time to head to Jarsath Wastes and to Skyfire Mountains to kill Wurms for 25 Wurm meats, this is a rare update. Seems to update from any of the wurms.
Head back to Fisherman Quurp in the Reet Camp to receive your second Fungus Sample.
Talk to Ryvenar Sal'Vara back in the Skleross Camp in Jarsath Wastes. He will send you off to find an ancient map book.
Inspect a Book Case ( -836, -6, -105 ) Copy/waypoint -836, -6, -105 in the House of Circles in Rivervale.
Head to drafling tower. Inside click the book shelf to zone into The Tower of the Drafling: Elite Bixie Hive. Once inside, clear level 85^^^ Elite Bixie Soldiers (they respawn so dont die) until you get to the last room ( -146, 82, 54 ) Copy/waypoint -146, 82, 54 Click bookcase to spawn Persadura level 85^^^ named (gives AA but no loot & may spawn again right after she's killed). After fight Brenlo Bixiebopper IV will run out. Hail him to get Planes of Power: A Complete History! book.
"Now that I have the book of Maps, I need to locate the four missing pages. My only lead is that lost libraries had a copy of this book at one time!"(Each page is on a respawn timer about 5 minutes or more:
- Map page 1 - Ruins of Varsoon (tome of life room) ( 6, 5, 72 )
- Map page 2 - Nektropos Castle (library on table) ( -15, 14, 59 )
- Map page 3 - Stormhold Library (behind bookcases in middle of room) ( -118, -32, -141 )
- Map page 4 - South Qeynos Mage Tower (under the staircase @ red portal) ( 707, 41, 94 )

 (note that each page takes several minutes to respawn, for multiple rangers doing it)

Return to Ryvenar Sal'Vara
Head to Chardok to kill an ancient wyvern Severclaw level 86^^^ ( 758.01, -30.65, 218.44 ) Past the blue (second) gate and the red (third) gate. Auto spawns when you move near back wall. He has a knock back but is easier fight than The Enraged Wumpus. Need good dps, if you kill too slow mobs in area repop (though if you stay carefully in the corner against the walls while fighting him you can avoid aggro). Also, if you're standing in the wrong spot, he may spawn again, so be ready! It is a chest drop, so Each Ranger in group has to kill and loot chest.
Return to Ryvenar Sal'Vara to claim your bow! Congrats!

Rewards

Eagle's Talon (Fabled)

This quest is part of the Ranger Epic Weapon Timeline, and can only be started/completed by a member of that class of at least Level 80.

I wouldn't describe the updates for the 25 wurm meats as "rare", they were updating for me off every 4 or 5 mobs. Uncommon for sure and I once had a run of about 10 without an update but not as scary as the walkthrough suggests.

@@ Line 41: / Line 41: @@
 # Inspect a Book Case {{Loc|-836|-6|-105|uid=}} in the House of Circles in {{Zone|Rivervale|}}.
 # Head to drafling tower. Inside click the book shelf to zone into {{Instance|The Tower of the Drafling: Elite Bixie Hive|}}. Once inside, clear level 85^^^ Elite Bixie Soldiers (they respawn so dont die) until you get to the last room {{Loc|-146|82|54}} Click bookcase to spawn {{Named|Persadura|}} level 85^^^ named (gives AA but no loot & may spawn again right after she's killed). After fight {{NPC|Brenlo Bixiebopper IV|}} will run out. Hail him to get Planes of Power: A Complete History! book.
-# "Now that I have the book of Maps, I need to locate the four missing pages. My only lead is that lost libraries had a copy of this book at one time!":
+# "Now that I have the book of Maps, I need to locate the four missing pages. My only lead is that lost libraries had a copy of this book at one time!"(Each page is on a respawn timer about 5 minutes or more:
 #* Map page 1 - {{Zone|Ruins of Varsoon|}} (tome of life room) ( 6, 5, 72 )
 #* Map page 2 - {{Instance|Nektropos Castle|}} (library on table) ( -15, 14, 59 )