Response: After you win a challenge and count 8 or more total STR, claim 3 power for your House. (Limit 1 per phase.)

Who is meant to have a STR count of 8 or more?

We have been playing the total challenge strength (Attackers and Defenders) and someone has suggested it is the winner of the challenge that has to have 8 or more strength

If the later, is there a specific reason why TOTAL STR is used in the text

You. After you win and count.

Sorry. I'm in a hurry.

thanks Bomb - short and sweet response

"You...count" would mean you have to come up with the 8 STR on your own. "Total STR" is the proper term for what an attacker gets by adding up the individual STR of attacking characters, plus modifiers, to see who wins or loses the challenge.