Overview
The image shows a complete list of all the missions from the different characters in the game.
Mission list
The image shows a complete list of all the missions from the different characters in the game:
Scaveola: 12 missions
Videx: 12 missions
Khepra: 11 missions
Rho: 5 missions
Captix: 6 boss missions
Xerxetes: 5 missions from the Heretek DLC
Tiresus: 7 secret missions (press SPACE in the ship menu to access them)
https://live.staticflickr.com/65535/49811177666_d73ea9c477_o.jpg[live.staticflickr.com]
PS: the order or the missions seems to be irrelevant, but completing the final mission from Scaveola o Videx last will change the ending. Not completing any of their questlines will result in a neutral ending.
PPS: v2 updated on the 2020/12/22, added a 12th Videx mission as pointed out by @Meyniro