The Black Chocobo buffs all of your Birds with its Landfall trigger, not just itself
Each time Serra's Emissary enters the battlefield, it allows you to change the card type you gain protection from, so you can gain protection from whatever you think might be the biggest threat to you at the time
And yes, you have to exile it afterwards, but if youre bringing back a big bruiser, youll likely want to end the game on the spot, no
Thanks to being in white, you can also include token doublers like Mondrak, Glory Dominus to make even more copies of your dying creatures
Later it was part of an even better card drawing engine known as Necropotence
(Click the following to see the deck's tokens.) Doom Prevails Tokens 3x Villain // Robot Villain tokens 3x Villain // Shapeshifter tokens 2x Ape Villain // Copy tokens 2x Rogue // Treasure tokens 0009a_MTGMSH_TknBstr: Villain Token // Robot Villain Token 0009a_MTGMSH_TknBstr: Villain Token // Shapeshifter Token 0010a_MTGMSH_CmdrTkn: Ape Villain Token // Copy Token 0009a_MTGMSH_CmdrTkn: Rogue Token // Treasure Token (Back) Assemble a team of friends for your next game night