Q: I lost everything due to fires, a friend offered me funding to restart my business, in exchange he wants a 20% equity stake. Can I accept this deal under Islamic principles? Is it halal? He said its better I take the loan from him than the bank. Waiting for your response.
A: May (SWT_ make it easy for you and your family, Ameen.

If your friend is investing as a partner (aka: Musharakah) sharing in both profits and losses, it is halal. If it’s a loan with a fixed 20% return, it is haram due to Riba.
Who is it that will lend to Allah a goodly loan so that He may multiply it for him many times over? And it is Allah who withholds and grants abundance, and to Him you will be returned. (Quran)
Allah Certainly Knows Best.