aerith gainsborough mtg card MTGNexus put X +1/+1 counters on each legendary creature you control MTG Commander EDH Deck Aerith

Clever Impersonator costs 1 more mana than the Metamorph, requires UU in the casting cost when Metamorph needs no colored mana at all, isn't an artifact which makes it harder to tutor up in Blue (artifacts can be fetched with Fabricate and Tezzeret the Seeker), but the upside is that it can also copy enchantments and planeswalkers

Or Mind Controls for that matter

You may not be any less blockable just from being bigger but you are substantially harder to trade with as well as the obvious being more important to block due to the larger damage output

Minamo Scrollkeeper, Trusted Advisor, Doctor Octopus, Master Planner, Cecily, Haunted Mage/Eleven, the Mage, and Twenty-Toed Toad each increase your maximum hand size to a specific amount and might fit your deck's plan