Well here’s my opinion on your rework
" Q - Eternal Light: if plasma shield is destroyed by damage before expiring, its cooldown will be refreshed and half mana cost refunded."
Is overpowered because it’ll just make Tassadar shield a player over and over again depending on the situation like an unavoidable Flame Strike or Li-Ming combo, allowing Tassadar to re-shield the target making Mages extremely useless.
Raging storm : if an enemy remained within psionic storm for its full duration, a new psionic storm will be casted at the same location, this effect can repeat up to one more time.
Oh look, Orphea’s ult into a level 16 talent.
A - Recall : active , 100 second CD : target 1 ally hero on the map and after 3 seconds, teleport them beside Tassadar.
Do you want to make Lt. Morales Medivac redundant? Because Tassadar doesn’t need this.
W - Phase Disruption: enemies damaged by psionic storm have their armor reduced by 25% and any buffs from their allies are negated and instead turned into debuffs.
This is an extremely overpowered buff.
E- dimensional Phase: dimensional shift now allows Tassadar to go through terrain, if Tassadar would regain form while within terrain, he would be knocked out to the closed wall.
I don’t think this is needed.
W – Blinding storm: when inside a psionic storm, enemies have their cast range reduced by 50%
Slightly overpowered because of Psionic Storm’s massive range.
A – protective Stasis: active, 60 second: target allied hero is placed in stasis for up to 6 seconds, stasis can be canceled early by Tassadar or if Tassadar dies.
Overpowered making Kharazim’s ult redundant.
Q - Khala’s Embrace: for the first 1 second of being shielded by plasma shield, 100 % of its prevented damage will be recovered as health over 3 seconds after the shield is broken or expired.
This is kinda like Medivh’s talent except can shield more after 1 second.
Q - Khaydarin Legacy: quest,
-prevent damage to an ally hero by shielding them for 10,000. Reward, shield duration increased by 1 second and gain + 40% shielding
-prevent damage to an ally hero by shielding them for 30,000, Reward shield duration is now permanent on non-heroes and is increased by 1 second on heroes for every 10,000 damage prevented by plasma shield on allied heroes.
This seems kinda interesting but at the same time powerful, you can make Plasma Shield lasts almost forever if enough damage is prevented and combining it with the talents at 4.
Opinion:
Overall, what you did is ehh merely making Tassadar overpowered without any drawbacks and the half health half shield is taken by Fenix.