Mamoru is Captured by Metalia! - S1.E48

After school Usagi is walking home to find Mamoru standing on the other side of the bridge, they walk up to each other and he hugs her, then she starts crying out of happiness.

later Mamoru kills Kunzite and turns into Dark Endymion meanwhile the other Senshi are fighting an Younma and some how they end up get attacked by Endymion. whilst the other Senshi are fighting the Younma Mio gets killed by Endymion and after the other Senshi were attacked he aims at Usagi and hits but Usagi turns into sailor moon.

After sailor moon henshins (not exactly) she has a sword and Mamoru tells her to attack sailor moon looks at him and decides she will do so.

in the end Usagi kills Endymion and whilst shes get her run up Makoto, Ami and Rei yell at Usagi not to do it but Usagi doesn't listen because she knows what she must do