Sly army type misused component of a cycle from York (7,4)

I believe the answer is:

mystery play

I'm a little stuck... Click here to teach me more about this clue!

'component of a cycle from york' is the definition.
I can't tell whether this defines the answer.

'sly army type misused' is the wordplay.
'misused' indicates anagramming the letters.
'sly'+'army'+'type'='slyarmytype'
'slyarmytype' with letters rearranged gives 'MYSTERY PLAY'.

Can you help me to learn more?

(Other definitions for mystery play that I've seen before include "Medieval entertainment" , "Medieval religious enactment" , "Medieval production based on biblical characters" .)

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app