So I haven't finished the game fully yet, I read somewhere that you need to 100% missions to get the "true" ending (no spoilers please, I'm trying to avoid it).

Aside from Eltariel missions, nemesis missions, siege missions and challenges I have found/done 100% of everything. I don't think challenges count, as most of them are equipment or Tribal Showdowns. The last Eltariel mission is the Bright lord, so no worries there. But Siege missions are showing 63% and Nemesis missions are showing 85% complete, even though all missions under those options are showing as completed. I read somewhere that in the final missions, you capture a bunch of fortresses, which counts, is that the case for nemesis missions as well, or is this a bug?