It's important to note that black is not particularly great at having payoffs for creatures entering but does excel on death triggers, such as the one on Blood Artist
When you take out a Mega, you get +3 points, winning you the match
While I think a Commander like Sidar Jafar of Zhalfir is a little more constricting in terms of deck design compared to a Commander like Y'shtola, Night's Blessed, I do really like all the intricate synergies you can include in a Sidar deck You also have multiple ways to protect your board state from sweeper effects, like Knights' Charge and Guardian of Faith
Essentially, Aegislash can be put on the Bench and, as a result, your Active Mega Altaria EX does +30 DMG with the formers Cursed Metal ability
After 6 April 2011, players could buy cards from the Black and White series, which have a code to be digitally represented