In a setting where Anyone Can Die, this series is absolutely full of tearjerker moments.
Unicron: 0
The terror of an Elonian child suddenly having their world ripped up around them.
Unicron's casual, effortless slaughter of Knights trying to protect Elonia.
The discovery of remnants of Velocitron on Unicron, revealing exactly what happened to the mysteriously silent colony world and all who had been on it.
Arcee having to kill the helpless, trapped titan Emissary, who's attempts to stop what her perceives to be an attack are actually dooming the Elonians he's trying to protect.
Wheeljack: Heh. guess there's worse ways to go than savin' an entire-
The destruction of both Elonia and then Eukaris.
Unicron: 1
Caminus falling.
Dirge sacrificing himself and being brutally ripped apart while trying to save Lightbright and Sparkstalker.
Both this and utter nightmare fuel is the reveal of what happens to those Unicron devours.
The Mistress of Flame buying time for her people to escape, her last moments being telling her people to have faith.
Much more minor than most, but also counting is Bumblebee's look of disappointment that Starscream seems to be falling back into his old tricks.
The despair of the Solstar Order at the realisation the fact they could not save their planet, one member even bringing up how her children had perished in Unicron's attack.
