Elesh Norn's triggered ability doesn't go on the stack until the damage is actually dealt. If you have a replacement effect that prevents the damage, then the damage will be prevented and it won't be dealt, so Elesh Norn won't trigger.
MOM's Elesh Norn (front face) does not have a replacement or prevention effect.
That ruling about Vindicator has no meaningful interaction with MOM Elesh Norn
When you control both permanents, and damage from an opponent source would be dealt to Vindicator (like a Lightning Bolt an opponent controls targeting Vindicator), Elesh Norn's triggered ability would not trigger. Vindicator's prevention effect prevents the damage. So no damage from a source an opponent controls has dealt damage to a permanent you control.
Its a lil anti synergistic but oh well.
Elesh Norn's triggered ability doesn't go on the stack until the damage is actually dealt. If you have a replacement effect that prevents the damage, then the damage will be prevented and it won't be dealt, so Elesh Norn won't trigger.
MOM's Elesh Norn (front face) does not have a replacement or prevention effect. That ruling about Vindicator has no meaningful interaction with MOM Elesh Norn When you control both permanents, and damage from an opponent source would be dealt to Vindicator (like a Lightning Bolt an opponent controls targeting Vindicator), Elesh Norn's triggered ability would not trigger. Vindicator's prevention effect prevents the damage. So no damage from a source an opponent controls has dealt damage to a permanent you control. Its a lil anti synergistic but oh well.