So Shamrock, huh? Kinda want to call him Shams/Shamsy/Shammy. If he had a devil fruit, this would be a good time to reveal it. Probably safe to assume he's fully mirroring you-know-who.
We don't have anything conclusive yet, but I'm still getting the feeling either Harald wasn't such a great guy and was planning to ally with the WG to bring giants under the control (like it's been hinted they wanted for a long while) or it's the WG that killed him and spread a bunch of lies.
I was nervous Luffy would get himself into giant proportions of trouble but it's looking less and less like that's going to happen. Or at least if it does, it'll probably be a temporary misunderstanding. I hope they go back to Loki after the WG intruders leave. I don't want Luffy to see Shamsy yet. Feels like the wrong time for anything more than a near-miss.