It's a little tricky if you're not used to using diagonal slashing while moving. As it was said above start with the sword facing NE when you strike the orb, then...
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×move SE,SE,SE,SE,S, turn sword N, SE,E, turn sword NW, then S...
From there you should be able to retreat to the trap doors.
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And I can recall our caravel: a little wicker beetle shell with four fine maste and lateen sails,
its bearings on Cair Paravel. O my love, O it was a funny little thing to be the ones to've seen.
-Joanna Newsom "
Bridges and Balloons"