Boosts damage dealt by 50%.
Glimmer and Astra are specials with very straightforward effects: more damage. Glimmer has a charge time of two and grants +50% damage, while Astra has a long charge time of four and increases damage by +150%. Night Sky is the un-upgraded version of these skills. The large difference in charge time and eventual damage make them quite different from each other, despite having the same direct effect. Both scale directly off the damage that would be normally dealt from combat. Therefore, the foe’s defense or resistance matters quite a bit more than normal when calculating damage from these specials. Astra is notable for being one of few specials capable of reliably OHKO’ing opponents, provided the attack would deal decent damage regardless.
Unlike other specials, the damage from Glimmer/Astra varies hugely based on your opponent’s stats. It is much more effective on foes with low defense/resistance. Naturally, the higher the user’s attack, the more damage from the specials. But debuffs to an enemies’ defense or resistance will boost the power of these moves significantly. Seal, Threaten and Ploy skills all make great partners to Glimmer/Astra. Glimmer, with its low cooldown is best used as a duel finisher, whereas Astra is best used to KO a completely fresh enemy. Standard special cooldown reduction skills such as Heavy Blade, Quickened Pulse and Infantry Pulse can be used to get these skills ready quickly.
Glimmer can be found on meta builds due to its low cooldown. Dragon Units make excellent use of Glimmer due to their refined breaths targeting the lower defensive stat against ranged units. Bladetome users, likewise, can use Glimmer to deal astronomical levels of damage in a single hit. Weapons that grant "effective" damage such as Falchions, Wolf Tomes and the Poison Dagger have excellent synergy with Glimmer, as they already deal high damage and with Glimmer or Astra can turn a 2HKO into a OHKO. As a general rule, Glimmer and Astra tend to be more effective when the user has high Attack.
While these skills seemingly have great damage multipliers, the way the damage is calculated often makes these specials a poor choice compared to others. Using specials which deal damage based on the user’s stats more often than not gives them much higher multipliers, at similar cooldowns. Astra is still capable of dealing high damage, but be wary of enemies with high defenses, as the multiplier will be heavily reduced.
The counterpart to Glimmer, Moonbow, can be frequently more reliable than Glimmer since it allows your unit to break through high defenses. Glimmer fails to be of use against enemies that can easily sponge your attacks; Moonbow gives your unit an edge against these foes.