Realizing that even Super Saiyan Blue Kaio-ken was no match for Jiren, Goku decides to use his trump card: the Spirit Bomb. With help from most of Team Universe 7, Goku prepares a giant Spirit Bomb using the donation of energy. Though remarkably powerful, this attack was also near useless against Jiren, who effortlessly forced the energy ball back at Goku, striking him instead.
Though his attack was unsuccessful, being struck by the Universe 7's Spirit Bomb enabled Goku to break through into his deeper potential, achieving the Ultra Instinct -Sign- state.
Master Roshi commented that, even though Jiren overpowered the attack, the Universe 7's Spirit Bomb would have defeated Jiren, had he been hit by it.
This is supported by Vermoud stating that the energy of the Spirit Bomb had him worried (although he remained confident in Jiren). Arack also implied the energy ball possessed a good amount of energy, with Champa concerned that it seemed dangerous.