Cards without the symbol are not accepted, but Speed Duel cards can be used in the Yu-Gi-Oh
Conscript_Joe: Same reason why some prefer customs, or lone fighter, or standard
If it becomes unattached to a creature, that creature must be sacrificed, so it's best to send that creature into the thick of battle and let it die in a blaze of glory.
Since Zapdos has a sweet SIR in 151 and Articuno just got one in the newest Pokmon set Journey Together, it only makes sense that Moltres now gets a turn
Pioneer is also driving the interest and prices of a couple of recent planeswalkers: Chandra, Dressed to Kill (prerelease) jumped 42$ this week to $19 while The Wandering Emperor increased 21% to $32
The ability to sacrifice a creature at the beginning of ones end step, thus generating damage and at the same time still receiving a good mana buff, lets the player start with a good base into the opponents rounds