Name of the quest: If a Tree Falls In The Forest…

Description: For decades the poet Urdraxas has been an influential voice in Unfallen society, known for moving reflections on the beauty of nature, the importance of balance, and the simple pleasures in life. But he now grows old, and yearns to return to the Long Sleep. The transition of an Unfallen to their final stage in life is a moment of great significance, and a gesture of respect would be well received.

Choice 1: Pilgrimage

Description: Urdraxas wrote about the beauty of nature. A suitable place should be found for him to sink his roots.

Objective: Possess a new Large or Huge Forest planet

Outcome: Urdraxas has begun his metamorphosis surrounded by the unspoiled wilderness of (planet name). Admirers from across the galaxy have arrived to pay their respects and contemplate his writings, forming the seeds of a new colony. As this settlement grows, the location of his final resting place will be preserved, providing much needed green space in the middle of the new metropolis.

Reward: New Empire Improvement - O, Pioneers!

O, Pioneers!

Empire Improvement (Food)

The final work by the Unfallen poet Urdraxas spoke of journeying through the cosmos to find a place to lay down his roots. Many have found inspiration in his words, seeking their fortune in the untamed wilderness at the far reaches of your ever-expanding empire.

Effect:

+X Food for Y turns on recently colonized systems

Choice 2: Immortalization

Description: Urdraxas has always been a passionate advocate of Ecologist causes. Enshrining these ideals in law would be a fitting tribute.

Objective: Have at least X Ecologist laws active in your Empire

Outcome: Urdraxas’ ideals have taken root in your legal system. His writings are now necessary reading for legal scholars across your empire, much to the chagrin of those who prefer impenetrable legalese to flowery prose. Not all appreciate his work and grumble at being asked to step outside their usual area of expertise - but a bit of culture won’t kill them.

Reward: New unique system improvement - Arcadian Academy

Arcadian Academy

System Improvement

Located in an idyllic rural setting and featuring a curriculum based around the liberal arts, the Arcadian Academy educates the exceptional talented - or the exceptional rich. The galaxy’s elite send their children here to study, and, more importantly, to build connections.

Effect:

+X Science

+Y Influence

(Can only be built once per empire)

Choice 3 (Conditional): Celebration

Condition: At least one Guardian

Description: Urdraxas was always one to look on the bright side of life. His transformation into a Third should be celebrated.

Objective: Sacrifice a Guardian

Outcome: As clouds of smoke and Dust fill the air, your citizens - both Unfallen and other species - are brought closer together in celebration of Urdraxas’ metamorphosis. As they laugh and smile and dance and sing, the Unfallen poet can face the curtain with a bow.

Reward: Sacred Harvest provides a FIDSI boost

Good quest theme! You got my vote ;D But I think the reward for the first choice isn't attractive enough.

How will the quest be triggered? 

edit: How about "Ygdrasil" for the name? It's the the name of the worldtree from nordic mythology. The first, oldest and biggest tree, ever exited. It's death leads to Ragnarök, the end and rebirth of the world.

Made a few small edits to the original post. The wording of the description had been slightly tweaked, and the text for the outcomes of Choice 1 and 2 have been expanded a bit. I've also added some detail to the rewards for these choices, and hopefully made the reward for Choice 1 more attractive.

The Unfallen poet also has a name now - Urdraxas. I started with Yggdrasil, the name suggested by Aimer, and changed the spelling to be more in line with other Unfallen names (Egdraxel), then tweaked it a bit more until I was happy with how it sounded.