I'm a returning player and I cannot help but think about how sad it is to see that the astral schools and shadow were sorta kinda abandoned as the game went on. My prime of playing Wizard101 was during the Celestia release and so the fantasy of these schools are still near and dear to my heart.
I have had many ideas over the years and I want to share them because I do love these schools and hope we can see more in the future. Especially now with Lemuria and a whole list of new PvP oriented spells on the way it would be really cool to see Star, Sun, Moon, and Shadow get some love.
The Sun casting animation is gorgeous and needs to be more common. It would be cool if Sunblade can finally become available to Wizards by some means. The only idea I've had would be a sun spell that duplicates. This would be a really interesting option for gameplay that focuses on tempo control for multiple hits. IE you cast the Sun Enchant on a +25% Balance blade when you cast the Balance blade it will create 2 +25% non-stacking Balance blades on yourself. -I do acknowledge the major balance implications of this though for cards like Supercharge, Feint, set shields, but I haven't been able to think of much else for Sun-
Star still has multiple outlets of stats that we could get an aura for. Especially if we introduced some star auras that cost pips to cast we could provide some niche benefits for that cost: flat damage reduction rather than %resist would add an interesting option for battles. Pip cost aura: this could be added by either an aura that adds flat pip reduction or a +pip conservation aura. +5% outgoing Blades this probably would need to be an aura that you use pips for and an option to ensure that the affected and unaffected buffs don't stack is coding it to only add when in use [cast an iceblade with the aura on and it's a +40% iceblade, attack with aura on and it becomes a +45% ice blade]. Prism auras to convert your outgoing school damage, I see great potential with this for PvE questing, PvP strategizing and improving boss fights; could also add an aura that converts your school damage to Star school damage as a way to avoid resists and set shields at the cost of school blades, traps, and bubbles. Last ideas for Star is target negative auras. This would be casting an aura on an enemy that gives them a negative effect: +% specific school damage, -% incoming healing, -% power pip, -% accuracy. Balancing this would no doubt be tricky. I wonder if it would help or hinder balancing these if they were offset from regular auras: IE wizard can cast brace on themselves and have a -% accuracy aura cast on them, both auras remain active.
My moon and Shadow concepts are completely the same. I would love it if these two schools could become viable classes just to add flavor to the game and playstyle options. I envision crowns gear with unique cards and set bonuses to help make using specifically these schools a viable option. How this goes about: Shadow gear would offer the wizard shadow critical, outgoing shadow damage, significant shadow pip production and more item card options for shadow attacks. A set bonus could allow the wizard to hold a 3rd shadow pip and provide an item card for X shadow-pip-cost to summon a shadow support/damage minion (could be a fun way to revive some old characters). Moon gear doesn't need to offer too much in terms of spells. What moon school needs it Health, resist, and damage that carries over into your morph; which I have some ideas for. First simply provide Moon School damage and Crit while the gear provides item cards for new Polymorphs into Moon forms that use Moon damage based attacks. Or the other concept for that would be the crowns gear has waning damage and crit. Robe give +25% adaptive damage. Wearer is a Fire wizard, currently receives +0% damage damage from Robe. Wizard Polymorphs into Pteranodon, the +25% waning damage now activates into +25% storm damage. Basically gear stats that either activate upon polymorph or carry over into your polymorph.
I just wanted to share my thoughts and hopes that these schools can get some kind of love in the upcoming content updates. Like I said Celestia was my prime and I still hold to the fantasy of these schools. Hope they can become a little more supported and viable if even just to add some flavor to the game. So please comment any critiques or your own ideas for new spells in these secondary classes!
casting animation is gorgeous and needs to be more common. It would be cool if Sunblade can finally become available to Wizards by some means. The only idea I've had would be a sun spell that duplicates. This would be a really interesting option for gameplay that focuses on tempo control for multiple hits. IE you cast the Sun Enchant on a +25% Balance blade when you cast the Balance blade it will create 2 +25% non-stacking Balance blades on yourself. -I do acknowledge the major balance implications of this though for cards like Supercharge, Feint, set shields, but I haven't been able to think of much else for Sun- 
still has multiple outlets of stats that we could get an aura for. Especially if we introduced some star auras that cost pips to cast we could provide some niche benefits for that cost: flat damage reduction rather than %resist would add an interesting option for battles. Pip cost aura: this could be added by either an aura that adds flat pip reduction or a +pip conservation aura. +5% outgoing Blades this probably would need to be an aura that you use pips for and an option to ensure that the affected and unaffected buffs don't stack is coding it to only add when in use [cast an iceblade with the aura on and it's a +40% iceblade, attack with aura on and it becomes a +45% ice blade]. Prism auras to convert your outgoing school damage, I see great potential with this for PvE questing, PvP strategizing and improving boss fights; could also add an aura that converts your school damage to Star school damage as a way to avoid resists and set shields at the cost of school blades, traps, and bubbles.
and Shadow
concepts are completely the same. I would love it if these two schools could become viable classes just to add flavor to the game and playstyle options. I envision crowns gear with unique cards and set bonuses to help make using specifically these schools a viable option.