If Walker did not have the ability to sense the mana around him, then he wouldn't have noticed a shift in the wind elemental mana behind him. Shay had used the scale step to speed around him and appear ready to slash with her claws.
The only reaction Walker could make was to slash one of the twin blitz swords upward to parry the claws. He had been able to do this a few times with Gil's arrows but it was a tough time based skill to learn.
'The skill parry has been taken from the fencer system. The skill parry has been automatically learned.
Perry- 1 mana cost
The user focuses mana in to sword, short sword, saber, or similar weapon. This allows for a lighter and faster slash with the goal to deflect and block an attack from an opponent. This skill works very well with counter attack skills.'