Question
My start up received an offer of $1,000,000.00 debt with 20% return. I am not sure if I should accept it or not, the investor is from outside the US which is little weird to me.
Answer
In a startup, I would only accept debt (unless is convertible debt) if you have significant revenues to pay off the debt with your current cash flow and are looking just for extra cash to invest in growth without getting diluted.
Considering you are at a seed stage, thus no (significant) revenue, I wouldn't accept this, specially if they are also requesting a collateral.