Fleetwheel Cruisers enters-the-battlefield trigger answers the whole multiples issue pretty well
or unattach from a creature
Once you have finalized your playing card size, you need packaging that fits perfectly and looks on-brand
If your idea of an elf deck is heavily rooted in these denizens of Middle-earth, Galadriel of Lothlrien is the Simic commander for you
This is Dimir colors restricted to cast, costs 3 mana, and can only find a card if you have a colored legendary creature out, which the Ring tempting you helps with
It looks quite costly at 5BR, but in practice, The Balrog is usually far cheaper to play, as it costs 1 less for every permanent that was sacrificed this turn