Sachiel

Sachiel is the 3rd angel, though he is the first one seen in the show, as he appears in episode 1.
His name means "Covering of God", he is a Cherubim. Sachiel is resident of the 1st heaven and an "Angel of water"
In goetic lore, he is called a servitor of the 4 sub-princes of the infernal empire.
His appearance is that of a huge humanoid creature with a bird-like face, he entered Tokyo-3 from the sea (!). UN tried to destroy it with heavy artillery, but failed.
Shinji, just arrived in Tokyo-3 on notice from his father has to fight Sachiel in EVA-01, a plan destined to fail because he couldn't handle the Evangelion right away.
But on the brink of defeat, Unit-01 goes berserk and Sachiel soon is no more ... a clear sign right from the beginning, that EVA's are maybe more than just ghostless machines, which shall be prooved later in the series.