The question was, "who would serve as 13th Age-style icons if you were to run a Thunder Rifts campaign using 13th Age?" You can learn the basics about 13th Age icons here: http://www.13thagesrd.com/icons/. They aren't just important as a means of tying PCs to the setting and providing the GM with hooks for inspiration and improvisation, but they provide mechanical crunch, too.
The possible answers were:
- Use a list of NPCs from Thunder Rift and "elevate" them to have the influence of icons in your version of Thunder Rift.
- Use the list from the default 13th Age setting, either introducing new NPCs and factions or imbuing existing NPCs with some of these icons' characteristics.
- Start play with Thunder Rift hidden from the icons (or all but one), then play out what happens when the existence of TR is revealed to the broader world and its icons. The PCs can help shape the place of Thunder Rift in this world that is now aware of it.
Given option three, what resources might the icons vie for? Natural resources? Sources of magic? New technologies? Unique monsters that could provide an edge if utilized in battle? Troops to turn the tide of war?