Right before launch, the client request a one-off new card layout that re-uses the card styling, but has different contents.
Instead of duplicating the card component and changing the contents, you can use your include as an embed where needed.
{# _news/index.twig #}
{% for entry in craft.entries({
section: "news",
limit: 10,
}).all() %}
<div>
{% embed "_components/card" only %}
{% block main %}
One-off card content goes here.
{% endblock %}
{% endembed %}
</div>
{% endfor %}
{# _components/card.twig #}
{% set image = image ?? null %}
{% set heading = heading ?? "Lorem ipsum dolor sit amet" %}
{% set description = description ?? null %}
<div>
{% block main %}
{% if image %}
<img src="{{ image }}" alt="">
{% endif %}
<h3>{{ heading }}</h3>
{{ description }}
{% endblock %}
</div>