SPIDER-MAN versus TRI-SENTINEL
Where: Amazing Spider-man #329 When: February 1990
Why: David Michelinie How: Erik Larsen
The story so far...
Displeased with the failure of his plan to shuffle villains in the Acts of Vengeance storyline, the Norse god of mischief, Loki, leaves the Earth a little something to remember him by.
For believing him dead; Loki magically alters a trio of newly designed Sentinels to merge them into one masterpiece of magic and machine - the Tri-Sentinel!
Lucky for Manhattan, Spider-man has been imbued with the mysterious uni-power thanks to the aptly named Enigma Force. Gaining the cosmic awareness that had been denied to him, Spider-man instantly learns of his foe, and leaps into action to avert nuclear disaster!
Full Article: http://secretearths.blogspot.com/2006/04/spider-man-versus-tri-sentinel-power.html