>>8379361>Megatron enacts his revenge against the bots and cons by attacking Ratchet while alone on the Ark and forces him to revive Starscream, who he sends to attack both the Bots and Cons>Ratchet sacrifices himself to kill Megatron after warping in the explosives Megatron had planted on the Ark, Starscream comes to his senses and surrenders and joins Scorponok's cons>Scorponok remains leader for most of the remainder of the run, but most cons are displeased about him letting Starscream rejoin>Thunderwing takes control of the Cybertronian Cons, follows the Autobots as they begin their search for the lost Creation Matrix to use it in the fight against Unicron>Thunderwing gets the Matrix and fights the Autobots on the Ark, but is blasted out into space and is presumed dead along with the Matrix>The autobots find out Ratchet and Megatron are both alive, albeit in a fused state. They also discover that for Ratchet to live, so must Megatron>Starscream jumps ship from Scorponok's group, joins up with Shockwave and some other cons and starts a Decepticon Civil War>The fighting is stopped when Prime intervenes, and Primus warps all transformers on Earth back to Cybertron to fight Unicron>Scorponok dies fighting Unicron, a Matrix-possessed Thunderwing brings the Matrix back to Cybertron but is killed>After the fight with Unicron Bludgeon leads what's left of the Decepticons until the end of the comicThere's also some stuff about Starscream, Shockwave, Megatron, Ratchet, and Galvatron II but it's not too important in the scheme of things.
tl;dr here's everyone who's been referred to as a leader of the Decepticons in Marvel G1:
>Megatron>Shockwave>Straxus>Galvatron (UK Only)>Cyclonus and Scourge (UK Only)>Soundwave (UK Only)>Ratbat>Scorponok>Three Decepticon leaders whose names I'm too lazy to look up right now (UK Only)>Straxus masquerading as Megatron (UK Only)>Thunderwing>Bludgeon 