First of all, having a lone Legendary weapon is kinda strange, but okay.
In terms of power level, this card is above the roof, even if it's not a spectacular effect like most Legendaries. 3 mana 2/3 weapon is okay, but the fact it draws a whopping three cards is amazing. It really puts Livewire Lance to shame, and that card wasn't bad at all. That said... Warrior doesn't have Pirates anymore.
It s a very stromg card for faster pirate wariors and I think it will get support in the next expnsions. Which will be cool if the pirates aren t super fast oppresive strategies (pretty much the strategy that is now). But there is a liability with this- it can only be a single copy per deck and if it somehow get s out of hand weapon removal is always in the game. Overall i like this more than the legendary weapons in the past since the warlock weapon was jist bonkers and some others sucked really hard...
It's probably a set up for a future expansion. Right now Warrior has no pirates in standard, and the neutral ones are probably not worth it. But there are a lot of cards in this set that synergize well with Rastakhan's Rumble (Voone anyone?), so they might add some support later.