Though it hasnt been explained in detail by Wizards of the Coast, it seems fairly obvious that their licensing deal with Marvel/Disney only covers them for printing a set physically, and not using the comic book characters and settings digitally
Jace's Triumph, Jace's Sentinel, and Jace's Projection all reward you for controlling any Jace planeswalker card, and there are a couple other admittedly weak Planeswalker Deck cards that tutor up various versions of Jace
This has little to do with bounce lands other than they have a slightly similar feel
Fellwar Stone Ain't no such thing as too much mana, and Commander rewards playing cards that scale with the number of players at a table, making Fellwar Stone a welcome addition to power-hungry, multi-color decks
On the plus side you draw a card whenever a land enters the graveyard from anywhere
First off, we have a full playset of Double Masters Force of Wills in Near Mint