According to Carlie and Ange's commentary, look out for these highlights in their 1x12 reaction:
The full reaction for the Season 1 finale is available on their official YouTube channel . Carlie and Ange One Punch Man 1x12 Miniplayer
The reaction portion of this specific video typically starts after their intro and OP cover (around the 1:25 mark). According to Carlie and Ange's commentary, look out