I posted this ca. 30 minutes ago but since the thread has picked up to the now usual chaotic speed I'm posting it again. It's a chunk of text taken from the top of my head regarding some of the pivotal characters and factions that appear to be ripe for amassing in to a unified force to repel and destroy the Reapers from my observations.
What I'm
about to list will be heavily influenced by the decisions made through both ME1
and ME2, so results may vary from person to person. Given the hints and at
times outright confirmations in ME2 of what we can expect in ME3
(depending on our personal Shepard), the following appear likely to play a
pivotal role in ME3:
1) The Rachni - The Asari messenger for the Rachni queen flat out states that
the Rachni queen looks forward to fighting the "Dark Ones" (aka.
Reapers) side by side with Shepard. Apparently the Rachni Wars were a result of
the corrupting influence of Reapers (see: Cerberus IFF science team) which
drove them insane and prompted them to attack Council space.
2) The Geth - Presuming that Legion has been truthful it appears the Geth may
be fairly peaceful as long as they are not attacked first (they will act in
self-defence) and are far more concerned with determing their own insular
future. If you opted to destroy the virus with the Heretics and not destroy the
space station, it remains uncertain what sort of shock effect the previously
virus infected Geth (then known as Heretics) will have on the larger Geth entity
as all memories and experiences are shared and stored. It could lead to pivotal
clues and insight about Reaper tactics and weaknesses which could be exploited.
3) The Quarians - The quarians lot is tied to the Geth. Legion states that the
Geth do not think poorly of the quarians for hating them since it is part of
their organic make-up. The Geth do not live on the quarian homeworld but
instead reside in space stations mining asteroids and cleaning up/care taking
for the quarian homeworld and other former colonies damaged during the Geth
uprising (which seems to have been started by the quarians resulting in the
Geth enter self-defence mode) in the "Dawn War". The Geth are opposed
to the Reapers because they want to create their own future without assistance
from outside; the Geth that did not follow this approach became the Heretics
which have now either been cured (hopefully) or destroyed (if you blew up the
space station). Legion mentions that the Geth can not bring about peace with
the quarians on their own, that the quarians have to be willing to sue for
peace as well. This seems to strongly hint at the possibility of establishing a
peace agreement between the two factions which might result in the vast quarian
fleet (not state of the art mind you, and not all military grade vessels) being
put to use against the Reapers. It might also provide a means by which the
quarians could finally reclaim their homeworld peacefully without resorting to
war as was discussed during Tali's loyalty quest. Whether Tali will be invited
to take her father's seat at the admirality remains unknown. It seems likely
Tali and Legion will serve as liasons for each of their factions in some
capacity (if either or both of them died in ME2 that changes the dynamics
significantly).
4) Krogans - Mordin's soul searching at Shepard's prompting may lead to Mordin
eventually finishing the work on a cure for the genophage that his former
assistant began (Moridin helped engineer some of the latest genophage
alterations and thus has first hand knowledge of it's structure). This will
also depend upon whether or not you opt to destroy the lab work amassed by
Mordin's former assistant. Should the burden of the genophage be lifted from
the Krogans it is not unthinkable that it would set in to motion a
reinvigorated spitire amongst the Krogans not seen in centuries and perhaps
cause them to band together under Wrex (if you didn't kill him in ME1) who
might then be persuaded to assist Shepard with the Krogan's martial prowess.
5) Cerberus - In one of the N7 missions (if I recall correctly) Shepard is
asked to retrieve sensitive data about Cerberus which you can then return to
Cerberus, the Alliance or keep for yourself and haev EDI analyse (the AI
informs you that it will take her the better part of a year to fully analyse
but apperas to contain revelations about illicit covert Cerberus programs that
would weaken Cerberus' standing). Whether such knowledge could be used to
coerce the Illusive Man and Cerberus in to accepting Shepard's plans over their
own against the Reapers (whom Cerberus already oppose), or be used to outright
undermine and possibly destroy Cerberus is unknown. Cerberus does have
extensive resources and connections which could make for a vital strategic
resource against the Reapers.
6) The aging sun/dark energy phenomenon near Haelstrom - This may be a Heretic
experiment, now become Geth, which may help shine some light on it since
Shepard has contact with Legion. What it's purpose is remains unknown but
it could be an energy source, a weapon or perhaps some means of transportation
to another dimension or even place in time dealing with the Reapers past
(perhaps a mission back in time when the Reapers were first created? This
would echo the Neanderthal flashback Shepard has in ME1 after receiving
the Consort's gift and visiting a certain planetary ruin).
Any additions, alterations, other?