IIRC even the Asylum Demon was able to shatter huge pillars, which in term of a straight fight is well past what Laios' party can deal with. Laios' party is street level (very lucky to reach even wall level) with FTE reactions. Marcelle can reach up to building level, but in DC only (her strongest protection spell wouldn't be able to save someone from a multi-story fall). As a verse, there is some decent power escalation towards the end though, but for the most part, Laios and his party are able to take them out by playing their smarts and with Laios' obsessive knowledge of monsters. I've yet finish the series though.