Editing Mastodontii (section)

===The Heresy===
[[File:Mastodontii_Post-Heresy.jpg|thumb|200px]]

The fall of the Mastodontii did not come because they were eager to join Hektor's revolt.  On the contrary, Tollund Ötztal's first order on hearing of the civil war was to forbid his men from taking sides.  Forces that were not already refitting at Tisenjoch were commanded to return home to prevent them from being drawn into the fray.  Unfortunately, Ötztal's good intentions were not enough to keep his Legion out of the war.  Tisenjoch's strategic location within the Loyalist cordon about Terra made its stated neutrality a matter of great concern to [[Alexandri of Rosskar]] and as the [[Silver Cataphracts]] Primarch was at full stretch overseeing the construction of defences, he asked [[Onyx the Indestructible]] to call on the Mastodontii to aid the Loyalists or - if necessary - eliminate the threat they posed.

It has often been speculated that Alexandri believed the latter possibility to be the most likely.  Certainly, sending Onyx to negotiate with Ötztal was a curious decision given the bad blood between the two if the Lord of Rosskar truly felt that the Mastodontii were a possible asset.  On the other hand, Alexandri may have simply felt that the Stone Men were too squeamish about the ruthless measures he was imposing in order to prepare his defence and just wanted them out of the way.  Regardless, Onyx's demands were not met to his satisfaction and the Stone Men began to attack Tisenjoch.

Initially, the Mastodontii were paralysed by indecision, especially at the highest levels.  Tollund Ötztal himself remained sequestered for some time, before meeting with his commanders and giving a short, chilling speech in which he declared that he was ready to take his brother's blood but that the Mastodontii would have to pay the price.  Though the Primarch's advisors were deeply unsettled by their lord's change in attitude, they could not deny that the time had come for decisive action or that the situation called for blood.  By using the most vicious tactics, the Mastodontii dispirited Onyx's men and saw them from the soil of Tisenjoch.  Once the defence was won, Tollund set to rebuilding his Legion, culling those who had hesitated to carry out his sadistic orders and forming the remainder into "hunting groups".  The new Mastodontii's first task was to exterminate the population of Tisenjoch and they excelled in this terrible duty.