Summons a possessed sword that follows the player. The sword will slash at nearby enemies in a wide arc.
If 30 seconds pass without a marked enemy being hit, the sword simply returns to the player's inventory and the skill starts a cooldown of 30 seconds.
Using the skill again while already summoned will recall it, allowing it to be held as a melee weapon.
Temporarily replaces the weapon that corresponds to the skill slot that Serenade is placed in.
For example: left skill slot will replace left weapon slot.
Pauses the unsummon timer while held.
Any strike made against an enemy will apply a mark to them, depending on whether they were struck by the flying sword or by the held sword; it is indicated by a red sword status icon for the former, and a blue icon for the latter. Marks can stack up to 5 times.
Strikes made while the opposite mark is applied will result in a critical hit, removing one mark and resetting the unsummon timer to 30 seconds.
In the Fractured Shrines there is an island that can be reached by platforming over invisible platforms; the rain splashes reveal their location. After that, there is a small gauntlet of traps that leads to a temple that can be entered either through the top 3 breakable floors, or through the other side where a door is.
In the building, there is a Stone Warden guarding a door which leads to a unique treasure room with a vault inside. Opening the vault will free Serenade, forcing it onto a skill slot. The blueprint itself goes in your inventory and still needs to be delivered to the Collector.
It is possible to obtain two Serenades (if one is legendary) and to use one as a melee weapon and the other as a summoned skill. This way, constant critical hits can be dealt to marked enemies, while avoiding the ability cooldown.