Plane of Sky Talon & Bulwark

Higher-level adventurers can traverse the island chains for new artifacts and new rare loot. The artifacts can be used on a new astral essence that has just appeared on the main island that transports the adventurers to new challenging bosses. You have to wonder though... why is this appearing now? What's behind it? This was one of the storyteller's favorite places, so he wants to hear every detail.

Complete a PoS chain, ensuring one person keeps all the shards along the way. Use the shards with the Astral Light on PoS to spawn the associated contruct with that chain. Again, one person should keep each of the construct shards as they are used to spawn the new PoS twins:

Chain Boss # of Shards to collect from chain:
Sun Chain Contruct of Radiance 4
Rain Chain Contruct of Storms 5
Night Chain Contruct of Shadows 5
Snow Chain Contruct of Frost 3
Desolation Chain Contruct of Sorrows 4

Turning in a shard from each construct will allow you to spawn the final twins, Talon and Bulwark. Note: they debuff resists plus stats.

Important note on shards. Think you have to do the chains all over again to loot the chain shards to spawn the constructs to loot the construct shards to spawn the new twins? Read this:
You actually don't have to do the entire chain over, and collect the shards, to spawn the construct. Once you've done a chain, and completed it, looted all that chains shards, and killed the related construct, speak with Wibble Gninogin in POS (by where you buy your keys) and he will sell you more shards to spawn the construct for 5k. This is repeatable again and again. So to re-do the pos twins, you just need to re-do the five constructs.
Note: Crimz says that AFTER you turn in your shards to the astral light, to spawn the construct, this is when you become flagged to re-purchase the shards. The flag does not come after you kill the construct. So if you spawn the construct and fail, it's all good, just head to Wibble and buy more and try again.

Tanking Data from Blackpearl:
Veeshan's Bulwark - Extremly high defense, swinging between 900-1200 on a 6850 AC Defender, AoE 2000. At least 2 stack CL's and 2-4 Necromancers needed to keep a 13200 HP, 6850 AC and all resists maxed Defender alive.
Talon's Veeshan - Very little HP's, swinging extremly hard, 2500s on a 6850 AC Defender, AoE 2000. At least 4 stack CL's and 3-4 Necromancers needed to keep the MT alive and the MT need extremly high HP and AC. Im raiding with 13200 HP's, 6850 AC and all resists maxed and even I got all the way down to 1 red at one point. Talon is definitely a beast, swinging as hard as Rallos Zek himself.
Bulwark much easier, a little harder than Norox and QoV so most should be able to tank him.
Info from Beowoulf, Cosa Nostra CLW:
..Talon has a decent size AoE that has about a 180 FR debuff on it, and the AoE is FR as well, (3500 dmg I believe). Bulwark has the same AoE but its CR in both the debuff and the dmg.

CS says:
Couple of administration points to clarify as well:
1. You turn in all five construct shards to the Astral Essence, chosing the option to feed it the multicoloured lights.
2. You are ported to the same location as where you've done the constructs.
3. The mobs won't spawn until you speak with the Astral Light on the other side BUT we believe the 30 min clock starts ticking the minute you port over. Remember, the port only takes 16 people. If you want more you have to coh them over from the other side (or LoS rez) and this eats into your 30 minute timer. You must be organized before you go.
4. The lag can be so bad (as with many mobs) that once you spawn them you can't see them. Talon spawns pretty much stratight in front of the portal where the constructs normally spawn, with Bulwark behind him. Talon's aggro range is long.
5. We just did Talon recently and as Black Pearl noted above, yup he hits hard.

RIP:
After killing Bulwark or Talon they despawn fast, within 5 minutes (and then you're ported off the island). There is not time to sort out ntl loot. Bulwark drops 4 NTL scales, and Talon drops 2 (TY Gonzales) and sometimes the NTL PoS gem (PoS self port). Make sure your raid force rolls for these BEFORE you engage the mobs or you'll never have the time to do after; they'll despawn without being looted. Everything else that drops is tradeable so have guildmaster loot and sort out rolls for loot later.

Whoever loots the scales can turn in to the Storyteller faction. Just speak with Wibble on the main PoS island first (TY RigorMortis), he gives you 100million xp also, then head to The Storyteller for 50 faction.