Given it's second pick, I'd pull Burst Lightning. You've passed a Disfigure, putting a strong signal black is open, and save Tuktuk Grunts, the red in the previous pack needs some commitment. Making a good cut on red can still put them off of red in time for pack 2 to have some decent cards.

Burst Lightning for me too. Mostly because I like to follow the BREAD as close as possible when drafting and there is clearly no bombs in the pack and the Burst Lightning is the best removal in the pack. So why not the hideous end? Because it can hit black creatures, and unless you fully commit to black, you will be playing against quite a bit of black cards and it could be a dead card. Also you can work Burst Lightning in better if you possibly go three colors. I know it can't kill creatures with 5+ toughness, but consistency is better than possibly having a dead card against heavy(or even all) black decks.

I would've gone with Armament master on the first pick. It's not too hard to draft a white Kor deck and there's a decent chance Brave the Elements would survive the round; also, if you did that you could've gone for the Aeronaut or the Bold Defense at the second pick.

[[Armament Master]] [[Brave the Elements]]
[[Kor Aeronaut]] [[Bold Defense]]

Seeing as you didn't do that, I'd take the burst lightning or the hideous end, but knowing that the first pack had the Disfigure and quite a few decent red cards, you know someone else will be competing with you for those colors so you'll get screwed on the second pack.

[[Hideous End]] [[Burst Lightning]]

Another option is to try to combo Trusty Machete with Quest for the Holy Relic but unless you have the Armament Master in the first place that's not a very good combo IMHO.

[[Quest for the Holy Relic]]

In the minority, I'd pick the Hideous End. Your neighbor isn't locked into Black: you passed them a Disfigure, but with an uncommon missing, you still might have picked a powerful Black card. So pick Hideous End for power level (a smidge higher than Burst Lightning overall). It's always appropriate to worry about signaling, but I would prioritize power level here. Your neighbor also took a powerful uncommon, so you're also still not sure what they'd pass you.

That said, with the given setup, Burst Lightning and Hideous End are both still very, very good choices. So I wouldn't worry too too much about the difference between them - you'd need to drag in more outside information like what you enjoy drafting, your personal estimation of power level of colors, and whether a relevant color is overdrafted by the people you're drafting with.