A D♯5 (D♯ Power Chord) chord contains the notes D#, A#. It is built from the formula 1 - 5, with D# as the root.
Is D♯5 the same as E♭5?
Yes — same two notes, same fingering, same fret. The two names describe one sound; which is correct depends on the key. Since this chord is used chromatically rather than diatonically here, the sharp spelling is the conventional one.