Whisker returned to Alex.
He wasn't sure how long it would take Alex to find a way into his Soul Space, and thus had to be there just in case he needed to go in.
Alex himself couldn't go into his Soul Space, and because of how small the radius of a person's Spiritual sense was in this world, Whisker worried that Alex couldn't reach every part of his Soul Space at once.
When he returned, Alex had just brought back the formation plate, upon which he had placed a decaying Sunheart and started using it. The formation was one that introduced a lot of mental anguish, which Alex couldn't deal with in any other way than to actually struggle through it.
He could use his Intent to lower the effect of the formation upon himself, but that was completely counterintuitive to his need to improve his pain tolerance, so that wasn't an option.
