Once it triggers, prowess isn't connected to the spell that caused it to trigger. If that spell is countered, prowess will still resolve.
Abbot of Keral Keep
Unless an effect allows you to play additional lands that turn, you can play a land card exiled with Abbot of Keral Keep's ability only if you haven't played a land yet that turn.
Any spell you cast that doesn't have the type creature will cause prowess to trigger. If a spell has multiple types, and one of those types is creature (such as an artifact creature), casting it won't cause prowess to trigger. Playing a land also won't cause prowess to trigger.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Anna Steinbauer
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
