Mazingkaiser SKL. Recently announced a few months back, is a brand new OVA series for the Mazinger series. Not much info about it can be found so far. However, the site for it has finally posted a PV to keep SR fans drooling till further news come up.
P.S. First ever mazinger to use a gun. Doesn’t look like it can use breast fire though.
Source: マジンカイザーSKL main site