Thread:SuperSaiyan2Link/@comment-32220816-20190811043544/@comment-25760276-20190811195925

Many of the elemental powers Akihiro wields is innate. His control over fire comes from his own limited knowledge of pyrokinesis. So wielding the other Royal Swords wouldn't let him necessarily be able to control water/earth with his own hands.

The swords themselves are a different story. While Akihiro himself wouldn't be able to conjure earth or water with his own body when wielding the Pegasus Sword, he would be able to use abilities that the swords innately have, like a water-version of the Flare Spin, etc.

TL:DR, wielding the Pegasus Sword would let him control the other two elements of earth and water using the blade, but he himself would not be able to summon water/earth the way he does fire.