Once he chose to summon the nine-star [Thundurus], he naturally could no longer summon the twelve-star [Thundurus]. Unless that nine-star [Thundurus] died in battle first.
Dark had conducted detailed tests on the mechanics of the [Heaven Summoning Technique].
He had confirmed that, at any given time, only one "true projection" could be summoned for the same target. However, this did not restrict repeated summons of the same target.
—Provided that the summon target still had sufficient ability to answer the summon. Responding to a summon and separating a projection to descend consumed no small amount of the summon target's power.
Even if the summon target was a [God], it could not be summoned infinitely and without restraint. [Thundurus] was a prime example.
The prerequisite for [Thundurus] to answer a summon was the Possession of Thunder God Ramon. However, Ramon had not fully revived, and the energy required was supplied by [Thundurus] itself. And [Thundurus] was only a fifteen-star Magic Spirit.
Its power could only support one fifteen-star summon, or two twelve-star summons. Beyond one fifteen-star summon and two twelve-star summons, it still had enough strength left to answer at least one nine-star summon.
After that, it needed a certain amount of time to recover before it could answer another summon.
Meanwhile, [Slifer the Sky Dragon], which lacked the consciousness Possession of a [True God], could barely answer a single fifteen-star summon. By comparison, if the summon target was [Saint], then so long as Veronica truly existed within [Magic Guidance Heaven], she could be summoned at the fifteen-star level multiple times without any concern that she would be unable to respond.
This was the support a complete [True God] could provide.
In the eyes of some, this kind of "off-field assistance" might have been equivalent to "cheating." But since Magic Guidance