Moving on.
MB3 Annotation 57...
Ruin's consciousness—separate from his power—isn't a particularly nice being. But you can't much blame him, as there's very little that is left of the mind that once was. The force of Ruin has pretty well molded the mind to fit with the force's intent.
This supports my hypothesis. Long ago I said that when a mind is bound to a Shard, the greater time bound to it, the more the mind is shaped by that power. Points for me.
Actually, given the circumstances, it could be argued that Ruin was only able to shape Ati to such a degree because of Leras' betrayal.
Well, we don't know exactly what happened. But it seems likely that the powers were held by the humans involved long before Scandriel was even mooted. Ruin claims to Vin that he had held it for a long, long time.
And on the subject, I really do agree that Ruin isn't evil. Neither is Preservation. Both are deadly if left unchecked; the Lord Ruler's empire is what happens with Preservation on top, while HoA is what happens when Ruin has his day. Neither is ideal. Stopping both was needed.
At some point, Leras probably realized this. Being bound to Preservation, this was probably easier for him than it would have been for Ati.