Sequencer

Spell sequencers
Spell sequencers are items that can absorb defensive spells, and then cast those spells back again later. Sequencers may contain between one and three spells of any level, depending on the quality, and may cast back those spells either a given number of times per day (rest period), or deplete charges on the item until the item is exhausted.

Using a spell sequencer
Using a spell sequencer is simple: simply cast defensive spells (up to the storage limit on the sequencer) onto the sequencer item (via right-clicking on the item and using the radial to find the spell you need), then use the sequencer power. Sequencers often have two abilities: one to cast back stored spells, and one to erase the spells stored in the sequencer so different spells can be stored. It is thus important to make sure that you are using the correct item ability.

Spells cast using a sequencer are cast with an effective level of the total level of the character using them. This means that multiclass spellcasters can increase the effective level of their spells by using a sequencer. Once spells have been stored in a sequencer, they do not need to be recast (simply resting will recharge a sequencer that has limited uses per day). Exporting and importing your character into a new module will reset the spells on a sequencer (it will become blank again).

Scrolls or wands can be used to sequence spells that you cannot cast yourself.

Creating a spell sequencer
In the toolset, you will need to add the property "Cast spell: Sequencer" to the item. This is the bare minimum for a sequencer to work. If you wish to be able to reset the sequencer after spells have been cast onto it, you need to also add the "Clear sequencer" attribute.

Examples
There is a special spell sequencer staff created in the Interlude of Shadows of Undrentide by casting the three spells not on the staff itself, but on a glowing orb. The staff is then added to your inventory with those spells permanently set.

Other (more conventional) spell sequencers can be found in the Hordes of the Underdark campaign, one of which is available for sale in the starting town.