In Operation Maelstrom (near the end of Zeta Gundam), Char 
fought Hamaan to near death.  At the end of the episode, Char's 
Mobile Suit, the Type 100 was shown floating in space with the 
cockpit hatch opened.

From the ending of the Playstation version of Zeta Gundam,
it showed Char climbing out of the Type 100.  While he was still
drifting in space, he sensed that young AEUG ace pilot Camille
Vidan had gone bananas.  Char realized spacenoids could not
coexist with earthnoids any longer and decided that he would lead 
the liberation of spacenoids.

Although Char did not appear in the TV series ZZ Gundam, he
had been active behind the scenes watching the changing of times.
After Hamaan's death at the hands of ZZ Gundam's pilot Judo, Char
took the one time puppet of Hamaan, Mineva Zabi, into safety.
The place where Char was shown with Mineva resembled the place 
where he had kept Lahla Sun which was in Side 6 but I can not
be sure.

I am not sure that Char's jesture of taking Mineva is out of
kindness.  Rather, it took away the chance of someone trying
to use the Zabi name to gather forces again similar to what
Hamaan did.

Resurfacing again as the son of the space martyr Zion 
Daikun, Char formed his own Neo Zion movement and planned to 
liberate the spacenoids by dropping the asteroid Axis to earth.
Char claimed that this motion would remove the cause of all space
wars which was to destroy those who remained on earth.

While Char was busy being the leader of the Neo Zion, super 
newtype Amuro Rey also enrolled in special task force London
Bell.  London Bell's mission was to stop Neo Zion from 
contaminating earth.

Will Char and Amuro's rivalry ever end?  Well yes, they fought to
near death at the end of the movie Char's Counter Attack.  When 
Char ejected from his Sazabi, Amuro grabbed the escape pod with 
the Nu Gundam and pressed it into the asteroid Axis while trying 
to push the asteroid away from earth.

Even till the end, Char and Amuro blamed each other for 
Lahla's death.  At the conclusion of the movie, a glow was shown
coming from the Nu Gundam and this power deflected the asteroid
Axis away from earth.  Although it was never clearly stated, Char
and Amuro both died in the incident.  The great Char Aznable was
never seen again in Gundam history.