Devoted Combo wants to assemble Devoted Druid/Badgermole Cub plus Agatha's Soul Cauldron for a fast kill, so Force of Vigor can blow up Agatha's Soul Cauldron (and any other artifact/enchantment) for free by exiling a green card, which is huge against their engine. Collector Ouphe shuts off Agatha's Soul Cauldron's activated ability entirely while also stopping any mana rocks they might run, though note it doesn't stop Devoted Druid's innate untap ability since that's a creature ability, not an artifact one — it still denies Agatha's Soul Cauldron. Six provides a resilient body that blocks their small creatures and generates card advantage through retrace. Trim slow or fragile pieces like Summoner's Pact since we want to be proactive and not get too far behind their combo turns.