Sahaqiel is the Tenth Angel, and is physically the most massive, several dozen times larger than the Evangelion Units. Its physical shape is very symmetrical, and resembles single-cell organisms such as amoebas.
Sahaqiel is also the first Angel to attack from orbit. Its primary means of attack is to divide itself, using parts of its own body as bombs thrust at the surface of the Earth. It does this several times in order to learn to aim.
Another interesting aspect of Sahaqiel is that it is the first Angel to use an AT Field offensively. Until now AT Fields were always deployed as defensive barriers. Sahaqiel uses it to destroy several satellites in orbit, as well as to attack the surface. As Ritsuko Akagi points out, the devastation caused by its attacks from orbit are not caused by kinetic energy, but by its AT Field.
After withstanding an orbital bombardment by the U.N. Forces using Nē Weapons, the Angel uses powerful jamming abilities to elude detection. When it is reacquired, it becomes clear that it is headed for New Tokyo-3. Ritsuko Akagi explains that with its powerful AT Field, the Angel could destroy all of New Tokyo-3 and NERV Headquarters just by impacting the general area.
As Sahaqiel makes its kamikaze run from orbit towards NERV Headquarters, the Evangelion Units are positioned around New Tokyo-3 in an attempt to intercept or 'catch' the Angel by simultaneously deploying their own AT Fields.
Sahaqiel is ultimately defeated by the coordinated efforts of all three Evangelion Units. Evangelion Unit-01 catches the Angel, Evangelion Unit-00 pierces its AT Field, and Evangelion Unit-02 uses a Progressive Knife to destroy its Core. As a result Sahaqiel's AT Field dissolves and the Angel crumbles to the ground lifeless.