It's canon to the series.

The other paladins know that Keith is half-galra,and they don't judge him,they have accepted him.

Zarkon is Keith's father,but it's unknown to everyone.

Keith's mother disappeared when he was very young,and after he met shiro,they're kinda like siblings.

Zarkon has planned another attack on Voltron.

Skip to through the fight between the galra and the paladins.

Everyone is fighting.

Suddenly lance gets off-ballance and falls backwards,hitting his head a little.He sits up and shakes the dizziness away.

As he opens his eyes,he stares in horror as he sees a galra pointing their Lazer gun at him from afar.He freezes în place.

As the galra shoots,the sound makes everyone stop and look in the direction of them.

As lance blinks a few times,he suddenly notices Keith in front of him,protecting him and letting the Lazer shot hit him.

(You're Keith.)