Dyfed escorts Yawgmoth to Pyrulea to demonstrate her abilities as a Planeswalker to him
Aladdin is a Robin Hood-style outlaw rather than a street urchin
For other purposes, however, if a card refers to your commander, it means either the legendary creature or the legendary Background enchantment
Tarkir: Dragonstorm Commander (TDC) and Special Guests (SPG) are Commander-, Legacy-, and Vintage-legal sets, and individual cards are also legal where already available in other formats
The Lost Caverns of Ixalan [Powerful Creatures, Exploration, Ancient Power] The Lost Caverns of Ixalan decks take you on a cool adventure deep under the surface, hunting for treasure and hidden power
YUE gives the whole thing a cool-vs-heat contrast, pale blue at the center and everything around it on fire