Mr Fantastic Pick

Just hit lord with Reed and had some really good games with him but I'm wondering after this when is he a good pick?

His tanking utility is his reflect mode and his ability to give bonus health to other players. In this way, he feels like a weaker magneto. His damage also feels comparable to magneto's and his ult won't get a kill on a coordinated team unlike magneto's. Why would you ever pick him over a full kit tank or a full kit dps?