This is someone who's famous and brings your deal instant credibility and hotness. Create the illusion that there are more investors willing to put in money than you're willing to take. If you have the luxury of picking investors, pick the ones who can add the most value to your business in terms of connections and credibility. Float like a butterfly . When a potential investor offers a suggestion or criticism, either agree, find common ground or postpone a response until you can obtain more information.
Many entrepreneurs are so focused and passionate that they debate every suggestion and criticism.
They come across as headstrong, unable to budge and unwilling to take advice. Acknowledge the enemy. Look for value, not valuation. Take the money when it's offered. It means take the money that's being offered instead of hoping for a higher valuation and less dilution later.