I just bred an Ember-Magma pair for a lineage project and I was 100% certain that I wouldn't get an egg... and actually I got the first Legi egg out of a Legi - Ember pairing. All the other eggs I got over the last weeks from various Legendary - Ember pairing were Ember eggs and now of all times, when I didn't even expect any egg, I got a Magma? Weird But yeah, I guess it was just pure luck (the few other pairs I bred this week didn't lay any eggs, not even the common ones).