The Emblem will stay forever, even if Jace is destroyed.
113.1. Some effects put emblems into the command zone. An emblem is a marker used to represent an object that has one or more abilities, but no other characteristics.
113.2. An effect that creates an emblem is written “[Player] gets an emblem with [ability].” This ...
There are currently no cards that explicitly remove emblems. The only way to get rid of an emblem is by activating the last loyalty ability on Karn Liberated. This restarts the game, and resets everything in the game except a specific set of cards that he keeps track of.
Mechanically, an emblem is intended to be a reward, in some sense, for completing a ...
No, not at this time.
o:emblem means the Oracle text (rules text) of the card must include the word "Emblem".
-t:planeswalker means the card must not have the type "Planeswalker".
The 18 cards that do mention "Emblem" are all Planeswalkers.
While not strictly speaking emblems, there are non-Planeswalker cards which create effects with durations of "for the rest of the game," which is the original wording for Elspeth, Knight Errant (before she was errataed to have an emblem).
Cyclopean Tomb removes mire counters that it put onto a land each turn for the rest of the game after it leaves the ...
One issue with the wording is that "remove from game" is text that MTG used to use prior to the 2010 rules update, and all cards that said to remove something from the game were given errata to say that they exile it instead.
Because of this, "remove this emblem from the game" could easily be confused with "exile this emblem", ...
Planeswalkers are the only sources of emblems
Mark Rosewater, the Head Designer for Magic, has said on his Tumblr blog that
We have chosen to make emblems a planeswalker-only thing.
That is one of many answers Mark has given regarding emblems, stretching at least as far back as 2011, and continuing to the present day, where Ascend (which is a "for the ...
As of today (Dec 24, 2014) there are 18 cards with Oracle wording that gives an emblem. As you can see, they are all Planeswalkers.
(source: this search here - I've cleaned up some un-necessary details for readability)
Ajani Steadfast Planeswalker — Ajani
Dack Fayden Planeswalker — Dack