Siege-Gang Commander is a great card, but every great commander is only as good as their lieutenants
For instance, Mark Herberholzs Pro Tour Honolulu-winning list featured the time-honored tradition of sideboarding in Blood Moons to ruin the hopes and dreams of Tron players
This card can be key to making a villain deck work, especially if you can pack in enough villainous ETBs
By paying two mana, you can turn Scion into any dragon from your deck for a turn, which means you always have access to the exact ability you need at the right moment
It also means that if the first character is exerted or damaged, the Shifted card on top will also be
But in regard to the top five cards I think will see a lot of play through Foundations lifetime, most of the ones I picked are low-cost, helpful cards with a strong impact on the board