For The Strongest Sage with the Weakest Crest Season 2 (also known as Shin no Nakama ja Nai to Yuusha no Party wo Oidasareta node, Henkyou de Slow Life suru Koto ni Shimashita 2nd Season — though note: the series you mentioned actually matches Shikkakumon no Saikyou Kenja ), a would be:
If you meant an actual (like for Crunchyroll or a fan site), then the most useful would be an episode-by-episode crest glossary and matchup timer — letting you jump directly to crest analysis scenes or battle conclusions without scrubbing. the strongest sage with the weakest crest s2