http://www.arcgames.com/en/forums/pwi/#/discussion/1201596/astrolab-system-pwi-riptideI'm gonna try my best to understand this system. It's highly confusing even with guides around.
What is a star chart?A star chart is a new equippable item that boosts your stat. It's like another form of gears like War Avatar Card is. The star chart's name is specific to each class, e.g. Star Chart: Sagesorrow for Mystic. Star chart is untradeable, unstashable, unable to be sold, unable to be dropped, and doesn't drop upon death. The only way to get rid of excess star chart is to infuse it to another star chart (similar to devouring a War Avatar Card to level another card).
There are four things that comes with this system:
1. Astral Infusion
2. Horoscope
3. Starshift
4. Stargazing
There are several possible stats that I've gotten (may be more):
1. Physical Attack
2. Magic Attack
3. Physical Penetration (new stat)
4. Magical Penetration (new stat)
5. Spirit
6. HP
7. Physical Defense
8. Earth Resistance
9. Wood Resistance
10. Water Resistance
11. Fire Resistance
12. Metal Resistance
13. Magic Resistance
14. Evasion
15. Accuracy
Astral Infusion (requires a star chart or Astrobana Pearl) Astral Infusion is basically similar to the devouring system on War Avatar Card. You infuse (get rid of) a star chart to another star chart. You will LOSE the star chart that you infuse, and make the equipped star chart stronger. Astral Infusion gives EXP whenever you infuse a star chart to another. The EXP is based on the infused star chart. For example, you have a level 1 Star Chart with 1 EXP and a level 3 equipped star chart with 18 EXP. When you infuse the level 1 to level 3, the level 1 star chart will be gone and fused with the level 3. So now, your level 3 Star Chart will have 19 EXP. The other way around also works. There is no EXP penalty for infusing a level 3 into a level 1 (higher to lower levels). So, you will still get 19 EXP in this case.
The catch with Star Chart as opposed to War Avatar is that you can choose which aptitude (the help button says attributes, but it's actually aptitude. It's not the stats such as mag atk, phys atk, and etc that is transferred. It transfers the aptitudes instead) you want to keep. It gives you the option to "Keep Previous" or "Select New" aptitudes. For example, with the same situation above, you infuse a level 1 to a level 3, it gives you the option to choose which aptitudes you want to keep. Since you equip the level 3 chart, "Keep Previous" means that you will keep the aptitudes on level 3 chart and only gain additional EXP from the level 1. If you choose "Select New", you will LOSE the aptitudes on level 3 chart, and instead gain the aptitudes from level 1 chart. The final EXP is the same in both cases. Be very careful before clicking any of this button. No pop-up window showing up that asks "Are you sure you want to "Get New Attributes"?. You don't wanna lose the aptitudes you want to keep.
**More aptitude explanation under Starshift section**To keep the stats (phys atk, mag atk, and etc.), you have to equip the star chart with the stats that you want to keep. That is the only way to keep the stats when infusing.
Astrobana Pearl simply adds EXP to your equipped Star Chart. Level 1 Pearl gives you 1 EXP. I assume level 2 gives 2 EXP, level 3 gives 3 EXP, and etc.
Horoscope (requires Nebula Dust Orb)Horoscope is basically the "reroll" stat button. It's similar to how you reroll engraving on your equips, rerolling the stats on your T3 gears, and etc. However, unlike engraving and reforge, horoscope randomly reroll the stat types, how many stats, and birthstar/fatestar nodes. Because of this, it is advisable to have at least 2 star charts (1 equipped, 1 in inventory). You don't wanna ruin your 6 stats on a star chart, because you can get unlucky and get only 1 stat on the next reroll. Equip a star chart with the best stats/higher level among the two. Whenever you get a Nebula Dust Orb, equip the star chart that you want to reroll. Click on the horoscope button. You will see that the stat types, number of stats added, and the nodes position changes.
While I'm at it, birthstar is the five middle nodes in the center of the star. Fatestar is the five outer nodes on the star. Fatestar requires at least 2 adjacent birthstars activated. Fatestar may or may not be activated with 2 adjacent birthstars (e.g. my current best Star Chart has all five birthstars activated and no fatestar). Fatestar gives better stats compared to birthstar. The number of nodes activated corresponds to the number of stats you have on your Star Chart (e.g. I have all 5 birthstars activated and no fatestar. That means my Star Chart has five stats in it). You'll notice this when clicking/targeting on someone with a Star Chart equipped. It gives an aura that shows how many stats activated. The maximum of stats that you can activate is 10 (five maximum for birthstar and five maximum for fatestar).
Video that shows Star Chart aura:
https://www.youtube.com/watch?v=sft27QRKMuM1 = white
2 = blue
3 = green
4 = green (bigger aura)
5 = purple
6 = fiery red
7 = yellow triangle
8 = fiery yellow triangle
9 = black skull
10 = rainbow
The minimum amount of stats that you get when rerolling depends on the level of your astral energy. Astral energy is the purple bar on the right side of the star. It gains 1 EXP per Nebula Dust Orb you use. Level 1 Astral Energy gives you random possible stats from 1-10. Level 2 gives you random possible stats from 2-10, and etc. The chance on getting 10 possible stats when you only have level 1 Astral Energy is extremely low, almost impossible (look up the first link for the % chance).
Starshift (requires Astrospira Pearl)Starshift increases the aptitude of a birthstar node. The aptitude of a fatestar equals to the sum of two adjacent birthstars that activate the said fatestar. The minimum aptitude is 1.00 per birthstar (2.00 per fatestar), the maximum is 5.00 per birthstar (10.00 per fatestar). Aptitude supposedly improves the stats, although I haven't seen any changes with 5.88 aptitude total. Astrospira Pearl comes in 3 levels: level 1, 2, and 3. Level 1 increases the aptitude of a random birthstar by 0.02. Level 2 and 3 are currently not available in game.
There are two buttons when you click on Starshift. The "Starshift" button will use 1 Astrospira Pearl to randomly adds an aptitude for a birthstar. The "Quantity Starshift" button will continously use the Astrospira Pearl on your bag (kinda like batch devour button on War Avatar) until there is no more spiras. You can click "Cancel" anytime you want to stop starshifting.
Stargazing (requires Starseeker Powder)Stargazing basically changes the pattern of the activated nodes on your equipped star chart. So for example, I have all 5 birthstar nodes activated and 0 fatestar node. When I use stargazing, the nodes will randomly change pattern to 3 birthstars and 2 fatestars, 4 birthstars and 1 fatestar, or all 5 birthstars again but the stat position changes. The stats themselves don't change. So, if you have HP/pdef/phys atk/mag atk/mdef for example, you will retain the same stats after stargazing. To gain a new/different stat, you need to use horoscope.
Stargazing is useful if you have a higher aptitude on one of the nodes, and you want to put your best stat on that node. It is also useful if you wanna put your best stat on a fatestar instead of a birthstar. It is advisable to save Stargazing until you have all the stats you want. So far, the only way to get Starseeker Powder is from Alexander NPC (one-time quest). It is rumored to be available in boutique later on, so it's gonna be costly for non-csers.