Guile

A spell exiled this way was never actually countered.

Although this ability triggers when the Incarnation is put into a graveyard from the battlefield, it doesn't *specifically* trigger on leaving the battlefield, so it doesn't behave like other leaves-the-battlefield abilities. The ability will trigger from the graveyard.

Guile's second ability replaces "counter [a certain spell]" with "exile [a certain spell] and you may cast it without paying its mana cost." You have the option to cast it immediately upon its exile. If you choose not to, it remains exiled and you don't get another chance to cast it. If the spell or ability that tried to counter the spell has additional effects, it then continues to resolve.

If the Incarnation had lost this ability while on the battlefield (due to Lignify, for example) and then was destroyed, the ability would still trigger and it would get shuffled into its owner's library. However, if the Incarnation lost this ability when it was put into the graveyard (due to Yixlid Jailer, for example), the ability wouldn't trigger and the Incarnation would remain in the graveyard.