Potential Paths: Path 1: Utilize Pedagogical for its suite of tools which could be used to convert science-related materials into quizzes or summaries, suitable for a high school environment. Although it doesn’t explicitly mention a focus on science-based content, its ability to turn any content type into learning resources gives it a broad potential application. However, its beta status could pose some limitation. Path 2: Implement MagicSchool AI or Education CoPilot as these platforms offer lesson planning tools and automatically generate educational content and assessments. Although neither directly mentions science-based content, the flexibility in creating standards-aligned content can likely accommodate a wide range of subjects, including science. MagicSchool AI stands out for its adaptability in leveling reading materials for different proficiency levels.

Final Narrative: Based on your requirements - a platform suitable for casual relief teaching in a high school setting, centered around science-based content - I would highly recommend MagicSchool AI as a potent tool. This platform is like your virtual teacher's assistant, offering over 40 different tools that simplify various tasks for you, allowing more time to focus on your students.

Here's why MagicSchool AI could be the perfect match:

1. Lesson Planning: MagicSchool AI provides a library of plans tailored to different subjects, grade levels, and learning objectives. This means you can access and tailor high-quality science lessons quickly, saving you planning time.

2. Content Generation: You can create original and standards-aligned educational content quickly. This is advantageous when you need to whip up science-based content on-the-go.

3. Assessment Creation: It generates custom assessments aligned with the curriculum and learning objectives, ensuring you can evaluate student learning promptly and accurately.

4. Text Leveling: This one is a standout feature. If your relief classes have varying levels of proficiency, MagicSchool AI can adapt reading materials to various proficiency levels within a classroom.

Currently, MagicSchool AI is offered free for teachers. So, you can actually implement it without any initial cost. Its intuitive interface enhances the user experience making it easy to use. While it plans to switch to a subscription model, they promise to have different plans designed to meet educators' needs and budgets.

As you explore MagicSchool AI, you may find the platform has even more features beneficial to your teaching approach and needs.