There's that button in battle that lets you refresh the page which is useful to skip the Team Burst animation and save some seconds of Enemy Debuff though
About your light team being your weakest, so is mine right there with my water team, just 1 SSR and 26K Attack with Mordred, notice I just have 1 month in the game, anyways I wish I could use Arthur or Mordred but my team is full of Buffers/Debuffers and I need a healer, so Andromeda it is
Edit: After a few hours of event I've noticed that with my light team I deal 11-13K Per Hime Hit and 250-280K In team Burst, compared to my Fire team's 15-16K Per hit and 240-270 Team Burst I think is a downgrade, plus I have a really solid fire team with no holes (Buffer, Debuffer, Healer, Buffer) I guess I'll just do this event with my 29k Mordred Fire Team