Lance

In .001 seconds all you'd see is a mushroom cloud the size of Antarctica.

A Fuckhuge LAZAR Turret about the size of an apartment building and a few football fields wide and long. Known to fuck all kinds of shit and ruin everyone's day. It's barrels are so fucking massive they could fire three story houses if needed. Mainly fitted on Imperial Navy ships and traitor fleet ships. Eldar have something like lances too but they aren't filled with hate like imperial ones.

Lances come in 3 fun sizes, single barreled to triple barreled. Doubles and triples go on anything larger than a battlecruiser.

The 'Lance' beam itself is a concentrated laser filled with FUCK YOU AND RAGE which is known to one-hit anything smaller than said battlecruisers. The Imperium also built a ship that spams lance turrets, in fact fires those turrets as Broadsides.