Conversation so far:
What is the new 52?
DC's 2011 relaunch of all of its monthly titles, The New 52.
Where is it set?
Arkham Asylum.
What is the Riddler up to in the new 52?
he sports a green mohawk in the shape of a question mark.
Is he in the asylum?
In DC's 2011 relaunch of all of its monthly titles, The New 52, Riddler appears as an inmate at Arkham Asylum.
Is the Joker there?
it is revealed that Joker has secretly hijacked Arkham Asylum.
Why did joker hijack it?
CANNOTANSWER.

Question: What does Riddler do?
Self-contained rewrite: What does Riddler do in the DC relaunch?