This card wants so badly to be a combo with
everything, its game text is phrased just about
as broadly as it's physically possible to be.
It's a proliferate card without proliferate, and
if it had infect it'd be adopted immediately in
Modern. It boosts things to ridiculous heights
in conjunction with the Theros block, and it
kills things outright in conjunction with the
Shadowmoor block. It's every planeswalker's new
friend and it's even a 3/3 for three. It wants
to be a combo with everything, and I think it
just about succeeds.
Maulfist Revolutionary is a single-shot
proliferate…or a double-shot of proliferate. You
can get more charge, energy, loyalty, +1/+1, or
other kinds of counters...or give your opponents
more poison counters, I suppose.
It does this twice, coming into play and dying.
It's also a 3/3 with trample for 3...green can
get slightly more efficient at this cost, but
this is definitely priced well in conjunction
with its abilities. I can see this doing damage
in Standard as an ancillary piece in some of the
counter-heavy decks.