The flavor text of old cards, the creatures, the legendary cards, the nonbasic landsall of them provide clues to the overarching story behind MTG
Limiting the number of lands in play to ten after making players sacrifice lands means that some players might end up with no lands in play and no way to play any more
It steals a creature when it dies, which while that can be very good, it just doesn't bring much to the table to make me want to have it as my commander
Entire deck archetypes and combos aren't usually catalyzed by a single bird creature card
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time
With a brand new stream having just happened, we now have a better idea about the Lord of the Rings mechanics