Eric Masterson first appeared in Thor #391 during the wonderful Tom Defalco and Ron Frenz's run on the title. Eric later became bonded to the Asgardian, transforming into the thunder God for a time. Eventually, Eric would gain his own heroic identity as Thunderstrike before eventually dying in Thunderstrike #24. Eric's young son, Kevin, would grow up and eventually take on his father's moniker as the second Thunderstrike in A-Next #1.
As a child Kevin found himself caught between his divorced parents as a rather painful custody battle played out. Kevin's mother, Marcy re-married football celebrity, Robert 'Bobby' Steele. Kevin's relationship with his step-father remained strained even as Kevin reached adulthood, as mentioned in A-Next #5. Kevin's paternal grandparents appear (unnamed) in Thunderstrike #2.
Hopefully I've done the Masterson's justice here, and I hope if I've made any errors that Messers Defalco and Frenz won't go to hard on me.
Until I find time to tackle the massive family trees I know everyone wants to see, I remain
frogoat