Do you mind describing more regarding on what you're trying to do with gcash? So that it will be answered if someone had an experience already with the one you want to try.
He probably have Gcash account with virtual debit card and he want's to use it to shop online. Since he is not in here in the Philippines he cannot buy or load his gcash account. But its quite suspicious on how he ends up with a verified gcash account, he probably buy it from someone.
Selling an account with your personal information is very dangerous, especially when it's a Gcash account. Gcash "Gcredits" is a feature that you can buy without money in your balance account.
It's like a loan that you can buy anything up to 5k pesos? Not sure how big it is, but when you use your identity, and the loan didn't fully pay, you will surely get into trouble.
I don't know where he bought the account, but the person who sells it, for sure, his identity will be risky.