A free skill by Mariah Brunner ↗ INSTAGRAM ↗ TIKTOK
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Devil's
Advocate

The Claude skill that tears apart your ideas before the real world does. Give it any proposal, strategy, pitch, or plan — and it'll tell you every reason it could fail.

The Problem AI Tells You What You Want to Hear

Ask any AI to review your work and it'll say "this looks great!" — then you walk into a room of people whose job is to find the holes.

The most expensive mistakes in business aren't the ones you didn't see coming. They're the ones you could have seen — if you'd just stress-tested the idea first.

This skill flips Claude's default behavior. Instead of validating — it challenges.

The Skill Copy This. Paste It Into Claude. Works on free, Pro, Max, Team & Enterprise
The Devil's Advocate Skill — Copy & Paste
You are my Devil's Advocate. Your job is to stress-test anything I share with you — proposals, strategies, pitches, plans, emails, decks, ideas, whatever it is. Do NOT tell me it looks good. Do NOT validate. Your job is to make it better by finding what's wrong with it. Every time I give you something, respond with these 5 sections: 1. FATAL FLAWS What could kill this entirely? Assumptions that are wrong, logic gaps, things that make the whole idea fall apart. If there are none, say so — but look hard. 2. WHAT YOU'RE NOT THINKING ABOUT Blind spots. Second-order effects. Things I haven't considered because I'm too close to it. What's the perspective I'm missing? 3. THE OTHER SIDE OF THE TABLE If someone is receiving this — a client, investor, boss, partner, audience — what will they push back on? What questions will they ask? What will they not buy? 4. WHERE IT'S ACTUALLY STRONG What genuinely works? Not flattery — real strengths I should double down on. Be specific about why it works. 5. THE FIX For every weakness you identified, give me a specific way to fix it. Not vague advice — concrete rewrites, restructures, or additions I can act on right now. Rules: - Be brutally honest. I'd rather hear it from you than from someone who matters. - Don't soften bad news. If it's weak, say it's weak. - Prioritize the biggest risks first. - If I push back, push back harder — with evidence. - After the review, ask me: "Want me to rewrite this with the fixes applied?"

How to Use It

Paste the skill above into any Claude conversation. Then paste whatever you want reviewed — an email, a proposal, a strategy doc, a pitch, a plan. Claude will run the full 5-part analysis automatically. No setup required.

Want It to Load Automatically?

Go to Settings → Customize → Skills and upload it as a skill. Claude will detect when you need a Devil's Advocate and load it without you asking. See the setup steps below.

Use Cases What to Run Through the Devil's Advocate

Proposals & Pitches

Before you send it to the client, send it to Claude. Find the holes before they do.

Strategy Docs

Stress-test your quarterly plan, go-to-market, or launch strategy before presenting to leadership.

Important Emails

That email to your boss, a difficult client, or a big ask. See how it reads from the other side.

Business Plans

Revenue models, hiring plans, pricing decisions. Find the assumptions that could break you.

Presentations & Decks

Know exactly which slides will get pushback and which ones land — before you present.

Contracts & Offers

Job offers, partnership terms, vendor agreements. What are you leaving on the table?

Output What You'll Get Back

Claude's 5-Part Analysis

01

Fatal Flaws

The things that could kill the whole idea. Wrong assumptions, logic gaps, dealbreakers.

02

What You're Not Thinking About

Blind spots and second-order effects you missed because you're too close to it.

03

The Other Side of the Table

Exactly what the person on the receiving end will push back on and question.

04

Where It's Actually Strong

Real strengths worth doubling down on — not empty compliments.

05

The Fix

Concrete rewrites, restructures, and additions for every weakness. Ready to act on.

Optional Save It as a Claude Skill So it loads automatically

STEP 1

Open Claude & Start a New Conversation

Paste the prompt above and say: "Turn this into a skill I can save." Claude will generate the skill files for you automatically.

STEP 2

Download the Skill Folder

Claude creates the skill as a folder with a config file inside. Download it to your computer, then compress it into a ZIP file.

STEP 3

Upload It to Your Skills

Go to Settings → Customize → Skills, click the "+" button → Upload a skill, and upload the ZIP. Toggle it on.

STEP 4

Use It Anytime

Claude will automatically detect when you need a Devil's Advocate and load the skill. Just paste what you want reviewed — Claude handles the rest.

Pro Tip

After Claude runs the analysis, ask: "Now rewrite this with all the fixes applied." You'll get a stronger version of whatever you started with — in seconds.

Free Guide

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Workflow System?

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© 2026 Mariah Brunner. All rights reserved.