This ability can bring in extra copies of threatening creatures like Aethersquall Ancient , or you can use it for energy generation by copying creatures who also generate energy when they enter the battlefield
The Satin Tower has a pretty accessible price range and provides some really great quality protection for your cards
They let you look at the top card of your library at any time, play lands, and cast Bird spells from there , and, most importantly, they double-trigger abilities that fire when a land or Bird you control enters the battlefield
Thats absolutely incredible, and Id be surprised if this werent one of reds stronger cards in Final Fantasy
The Animus, the relics of the Isu, even the weapons the Assassins themselves use can all be found as colo#rless cards
Your commander dictates almost everything about the 99 cards you put around it, and so it stands to reason that it would also shape your mana curve - that is, the casting costs of each other card in your deck