Need help ruling on a class ability (Eldritch Theurge, DnD 3.5)

[Hyooz]

The class ability in question:

Spellblast (Sp): This invocation (Lesser; 4th; Eldritch
Essence), learned at 3rd level, allows you to place an arcane spell that affects an area upon your eldritch blast. If the eldritc blast hits its target, the spell's area is centered on any corner of the target's space, even if the spell could normally be centered only on the caster. If the eldritch blast misses its target, the spell is lost with no effect. It takes a full-round action to cast the spell and fire the eldritch blast. Only an area spell with a casting time no greater than 1 standard action can be placed upon your eldritch blast. Only the first target of your eldritch blast is affected by the spell (for example, an eldritch chain spellblast centers the spell on the initial target, not on any of the secondary targets). If your eldritch blast doesn't specify a target, you can't apply thi
invocation to the blast. Treat spellblast as a spell whose level is equal to the area spell placed upon the eldritch blast (minimum 4th level).

The bolded part is the part in question. You place an area spell on an eldritch blast, and then it effects one target? I'm not sure what exactly this means. Help clarifying, please?

[Draken]

That is supposed to mean that, if you alter your eldritch blast with eldritch chain, for instance, only the first target of the eldritch blast "triggers" the effect of the spellblast (the area spell), the other targets of the eldritch chain do not trigger further spellblasts.

Basically you can't multiply the spell.

[monty]

Right, the spell goes off when it hits the first target as normal (and the spell can hit multiple targets if there are others), but if you hit multiple targets with the blast, the spell won't go off again.

[Hyooz]

Ok. That makes sense. There were some ideas tossed around that the spell only effected the first target. So you have a targeted cloudkill or something like that. The reasoning for that was area spells don't normally effect a target, but an area. He pointed to the spellsword class, but I'm not sure that ruling is right anyway.

Thanks.

[Draken]

Spellsword concentrates the area of the spell into a single target because that ability is, invariably, melee range. If it didn't concentrate the area, spellswords would not exist because they would just kill themselves with their own fireball slashes.