With all due respect, I think this is going TOOOO far. Someone doesn't become a Muslim because they lost a bet, or become Christian because they lacked knowledge, and vice versa.
To be a Muslim you believe that there is none worthy of worship except Allah, swt, and believe Muhammed is the messenger of Allah, swt. You MUST feel it in your heart and say it with your lips.
It's fine to discuss and debate, but Allah, swt guides whom He wills. There is no compulsion in religion, and that kind of consequence forces someone to follow something they don't believe in. Quite frankly, it sounds extremely arrogant, and arrogance is not becoming a Muslim either. It is a requirement of every Muslim to invite others to Islam, to show them the truth, and to do it with respect and kindness.
If seven, or any other nonmuslim, embraces Islam, it was only through the will and guidance of Allah, swt, and not because someone lost a challenge or debate.
May Allah, swt, forgive me if I have offended anyone, it is not my intent.
With respect,
Wasalam,
Hana