Bard takes away a powerful artifact during the Noxian Invasion of Ionia. Said artifact created a massive laser that was strong enough to disintegrate people and burn through an entire mountain. It makes me wonder when Bard had to intervene. Could there be anything in the champ lores could have pushed him into action?
It's been mentioned before he was there to witness the fall of Shurima, the Ruination, and activities the Frozen Watchers did. My personal assumptions as to those three things are as follows (but these are assumptions so bear that in mind):
Bard arrived during the Ruination to collect the magical artifacts that were stored on the island, as that would've been a dangerous place to leave them. Essentially he was on clean up duty on that day, making sure that the cause of the event was removed so that it wouldn't be an issue later on, even if the Ruination couldn't be stopped. He might've also helped Maokai survive the ordeal, but that's just me thinking on things.
Bard rescued Azir's third, soon to be born child during the fall of Shurima. It was vital he saved this child because the lineage of Shurima's dynasty is essentialy for events in the future, and so Bard had to save one of them, and chose the one that wouldn't effectively be missed, as they would lack perspective on the event and wouldn't change anything if they were a survivor. Effectively the child surviving in secret wouldn't have changed the course of history until the time was right, where as any other member of Azir's family would've potentially screwed things up for the future. He potentially had to fend off Xerath to protect the child, and buy time for Nasus and Renekton to appear. He would've then likely entrusted the child's well being to Nasus, as he'd be a better judge of how to best protect the mortal child in secret.
He bore witness to the fall of the Frozen Watcher's, but because the details about the conflict aren't so well known, I don't know what he did specifically. Since we lack details my current assumption is that he simply watched and observed in case anything went awry and needed his intervention, as it was a critical point in Runeterra's history. Potentially he might've hindered the Watcher's behind the scenes to allow the Iceborn to gain an advantage.
Again those are assumptions of mine and could be totally off base. Bard's probably had a few times where he's appeared in not so dire situations, but I think there's one more big thing that he might've done, though it's totally head canon at this point:
Riot teased that Bard had some actions in Freljord (most likely during the reign of the Watchers), the Fall of the Shurima Empire, the Ruination of Blessed Isles to Shadow Isles. Those are some I can recall.
All actions Bard takes mean the preservation of the universe. That means that if Bard were to do something horrible, it would be because the universe would suffer catastrophic, potentially fatal damage otherwise. The guy above me has pretty good examples
If Lamb and Wolf ever took off their Masks he would probably come to try to calm them down.
