He's PO'ed. As with Madelena, he was abducted in 2032 by the extraterrestrials and overdosed with Trinity. Fortunately for the both of them they had almost identical personalities, so both of them wound up the same way. Eric doesn't tolerate foolish individuals, hense his current state. Someone decided to yank on his tail while he wasn't looking and how he reacted, giving off an ancient threat before going off to be with Madelena. Later on in life he becomes a Colonel in the military before 'retiring' so he could carry on with paleontology as an immortal (the rest of his friends are all immortals thanks to the Lord our God - as much of a curse as a blessing, only at the end of time will they truly die).