It's from the Time Wars arc from Marvel UK #204, where Galvatron's presence with Megatron in the same timestream were causing the universe to unbind, and Fort Max/Scorponok/Soundwave/Magnus' teams teamed up to take down Galvatron and send him back to his timeline. Megatron's killing of Cyclonus (before he was even created) accelerated the destruction. Scorponok was pretty much underestimating Galvatron and got punched through, when Magnus' shabby aiming shot him instead. Scorpy's Cons then took revenge on Magnus...
This Mosaic's from the P.O.V of Galvatron btw. Galvatron at that time was having conflicting memories (one version from Megatron's perspective, and another from Galvatron's perspective). Before that, he saved Megatron from Roadbuster's cannon blast (cos he remembered being blasted by RB in this situation back when he was Megatron). But since he has now saved Megatron from that blast by taking it onto himself (hence his face damage), the past memory of being blasted as Megatron "didn't exist anymore" due to history being changed. This conflicting memory further drove Galvatron insane as he tried to connect the change in memory.
Better explained by a extract:
"As a mind already teetering on the edge of madness tries to grasp why present events conflict with those he once saw..."Anyway, nice art. Homages the original issue very well (including the sound effects)