Their order in the packs is based on how they come off the print sheet, which explains the rare Islands
That's a bit of a departure from how energy was originally used in the Kaladesh sets, where it wasn't tied to any super-thematic strategies
If a card with flashback is put into your graveyard during your turn, you can cast it if it's legal to do so before any other player can take any actions
My favorite on the squared corners is Feedback
2 Robin Hood, Champion Of Sherwood Never Challenge Him Getting the most out of your cards is vital in a game and Robin Hood, Champion of Sherwood gives you two solid abilities that can be played quickly and with a solid body to keep him swinging
This card also pairs nicely with the enchantment Hardened Scales which only costs one green mana, and gives you an additional counter onto a creature whenever any counter is added to it