There are two curent ways to get the megapohone in arsenal. The first way is in the shop, it may or may not come on the daliy shop. It is best to wait and save up for it and when it comes on the store buy it. It would cost 1200 battle bucks so save up for it. The other way is a litte harder but you can get it anytime. You may get it while opening a flair case. These cases contain announcers, kill effcets and emotes. The megaphone is an emote so you can get it by opeing lots of theese! Tho each case costs 600 battle bucks and the chaces of getting are very low so I recommend the first way. If you want to use it put it in one of your emote slots and there should be a new box where you type the sound id you want to play. Once your in game press g and tap the emote button and play the emote called megaphone then music or some other sound will play!