Re: multi power or sweep/two weapon fighting?
In a FH campaign, you generally pay points to buy skills
that let you use weapons in various ways. You get the
weapons "for free", for gold, mugged from a guard, or
wherever.
MPA would only apply to powers for which you payed
points which is how your super hero has a sword in a
Champions game. Note that MPA also requires that you
have more than one attack power to use at the same
time, e.g. you payed points for two swords.
Sweeping is available in either genre, but TWF seems
to be a kind of specialized sweep that requires two
separate weapons. It's certainly written up that way.
The two "weapons" can be be anything your character
could wield. They don't have to use the same maneuvers
either though each uses it's own OCV and you ending
up with the worst DCV. It also uses the whole phase
unless you also buy a Rapid Attack skill too. The main
difference from a Sweep is that a Sweep uses one kind
of attack multiple times.
The overlap between TWF, sweep, and MPA is annoying.
In some ways, you're better off building a Naked
Advantage Autofire with some limitations for the
number of points you end up spending along with the
DCV and phase penalties.