Transformers Fall of Cybertron Soundwave
Although Soundwave’s box shows him clearly holding a rifle, the toy does not have it (someone oughta sue!) So his only weapon is his shoulder cannon.
Soundwave comes with a disc launching gimmick. Popping the discs free from his chest, will (might) make the disc trigger auto transform, assuming it hits the floor trigger button side down. I think Soundwave can also hold up to 2 data discs at a time.
Though this isn’t officially in the manual, you can transform Soundwave into “device” mode. It appears in the Fall of Cybertron Game.
Data Disc mode
Unfortunately, Voyager Soundwave is just too big. Considering Megatron and most of the WFC/FOC figures are Deluxe class-sized
Then again, I guess Voyager scale is the only way to go if you want auto-transforming minions to be workable…?