The true "emergency firestarter" material is only what you can find around you. Learn to start a fire in any condition the size of a shot-glass and then keep it going and you're pretty much GTG.
As far as "hard core", I cheat. When out camping, I always carry three (redundancy is good) airtight/waterproof containers full of "strike anywhere" matches. Four to eight match sticks can be useful starter, and I have done that in wet conditions.
That aside, it gets much harder the more days it's been raining.
On the PNW coast, you can always find canopy to deflect the rain. For materials, there is moss (fast burning and hot), twigs (feeder) and sap. People think pine and fir needles, but if they're high moisture, they will absorb all the heat from your fire and put it out before they ignite.
In the Oregon, Cali and Nevada high desert, dry grass (a lot of it), bark from the sage brush and add twigs as you can.
As your fire builds heat, add bigger material. In the desert, trees and larger material can be hard to find. One spot, could only find enough to burn for 3 hours.
I'm not a fan of big fires, but if you manage your log placement and tend it regularly, you can achieve the "luminous flame" that projects more heat from the fire, making a small fire warm you as much as a big fire.
Edit to add: if you have some fatwood, you're living in luxury. That stuff is gold.