The challenge that Walker needed to push through was bonding an elemental plane temporarily to Remey.
This was easier said than done because she was not necessarily controlling space mana in ways that he would control spatial mana. Especially since her spatial storage skills that she gained were not normal like his that could store basic items. She had only gained one that allowed her to store potions she had made and some herbs.
Her spatial aspects were more related to alchemy rather than anything else. She didn't have one related to fighting because it just was not part of what her focus was. Her fighting skills had already developed well enough and she didn't experiment with them in terms of other mana like space in the ways that Walker did.
