<p>Night of Knives fills in a lot of the detail around the usurpation. Have you read it? </p>

<p>And you don't have to be an ascendant to kill/defeat an ascendant. </p><p>Due to your name I guess you have already read Midnight Tides. </p><p>There two Seregahl got killed by Bars and Ublala, despite the fact that they were gods of some sort. </p>

<p>The argument, though, could be that they lasted a lot longer and were subject to more...extreme attacks by Silchas, Iron Bars and Ubala.  </p><p>Laseen died by a knife thrust. </p>

<p>Kellenvand and Dancer spent I think 2 years in an Azath House gleening  info about gods and ascendants Laseen did what they ultimately wanted her to do in order to act independent from the empire </p>