I'm looking for a clarification for my group about the Invisible Spell feat from CityScape on how it interacts with Summon Monster (specifically Summon Undead).
The book states:
You can modify any spell you cast so that it carries no visual manifestation. All other aspects of the spell, including range, area, targets, and damage remain the same. Note that this feat has no bearing on any components required to cast the enhanced spell, so the spell's source might still be apparent, depending on the situation, despite its effects being unseen. For example, fireball cast by someone with this feat could be made invisible in the moment of its detonation, but everyone in the area would still feel the full effect (including the heat), and any flammable materials ignited by the explosion would still burn visibly with nonmagical fire. Those with detect magic, see invisibility, or true seeing spells or effects active at the time of the casting will see whatever visual manifestations typically accompany the spell.
Given that, would it make the summoned creature invisible, or mearly the magic surrounding the act of summoning invisible (and therefore be worthless)?
If the creature, would this invisibility act as regular Invisibility or Greater Invisibility, meaning if summoned creature does go invisible would it reappear when it makes an attack?