diff --git a/packages/coding-agent/.changes/error-message-warning-icon.md b/packages/coding-agent/.changes/error-message-warning-icon.md
new file mode 100644
index 000000000..d824da2b5
--- /dev/null
+++ b/packages/coding-agent/.changes/error-message-warning-icon.md
@@ -0,0 +1 @@
+- Added the `⚠` icon prefix to `showError` messages in the interactive TUI, matching the existing `showWarning` treatment ([ENG-6159](https://linear.app/primeintellect/issue/ENG-6159)).
diff --git a/packages/coding-agent/src/modes/interactive/interactive-mode.ts b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
index c6eb0cf5f..fa5a21313 100644
--- a/packages/coding-agent/src/modes/interactive/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
@@ -7576,7 +7576,7 @@ export class InteractiveMode {
 
 	showError(errorMessage: string): void {
 		this.chatContainer.addChild(new Spacer(1));
-		this.chatContainer.addChild(new Text(theme.fg("error", `Error: ${errorMessage}`), 1, 0));
+		this.chatContainer.addChild(new Text(theme.fg("error", `⚠ Error: ${errorMessage}`), 1, 0));
 		this.ui.requestRender();
 	}
 
diff --git a/packages/coding-agent/test/interactive-mode-status.test.ts b/packages/coding-agent/test/interactive-mode-status.test.ts
index 610b84b41..1bd0b4e7d 100644
--- a/packages/coding-agent/test/interactive-mode-status.test.ts
+++ b/packages/coding-agent/test/interactive-mode-status.test.ts
@@ -1301,6 +1301,17 @@ describe("InteractiveMode MCP command", () => {
 		expect(manager.getGlobalMcpServers()).toHaveProperty("fetch");
 	});
 
+	test("prefixes showError output with the warning icon like showWarning", () => {
+		const fakeThis = createRenderedMcpHarness(SettingsManager.inMemory({}));
+
+		fakeThis.showError("boom");
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toContain("⚠ Error: boom");
+
+		fakeThis.chatContainer.clear();
+		fakeThis.showWarning("careful");
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toContain("⚠ careful");
+	});
+
 	test("refreshes MCP providers before deferring a changed command while busy", async () => {
 		const manager = SettingsManager.inMemory({});
 		const events: string[] = [];
diff --git a/packages/tui/.changes/markdown-deep-heading-render.md b/packages/tui/.changes/markdown-deep-heading-render.md
new file mode 100644
index 000000000..2849da998
--- /dev/null
+++ b/packages/tui/.changes/markdown-deep-heading-render.md
@@ -0,0 +1 @@
+- Fixed deep markdown headings to render as formatted headings at all six levels instead of dumping raw `#` prefixes for H3-H6: h1 stays bold+underlined, h2/h3 are bold, h4 is bold+italic, and h5/h6 are italic, all in the heading color ([ENG-6159](https://linear.app/primeintellect/issue/ENG-6159)).
diff --git a/packages/tui/src/components/markdown.ts b/packages/tui/src/components/markdown.ts
index 704ce10b6..cf6919524 100644
--- a/packages/tui/src/components/markdown.ts
+++ b/packages/tui/src/components/markdown.ts
@@ -427,7 +427,6 @@ export class Markdown implements Component {
 		switch (token.type) {
 			case "heading": {
 				const headingLevel = token.depth;
-				const headingPrefix = `${"#".repeat(headingLevel)} `;
 
 				// Build a heading-specific style context so inline tokens (codespan, bold, etc.)
 				// restore heading styling after their own ANSI resets instead of falling back to
@@ -435,6 +434,10 @@ export class Markdown implements Component {
 				let headingStyleFn: (text: string) => string;
 				if (headingLevel === 1) {
 					headingStyleFn = (text: string) => this.theme.heading(this.theme.bold(this.theme.underline(text)));
+				} else if (headingLevel >= 5) {
+					headingStyleFn = (text: string) => this.theme.heading(this.theme.italic(text));
+				} else if (headingLevel === 4) {
+					headingStyleFn = (text: string) => this.theme.heading(this.theme.bold(this.theme.italic(text)));
 				} else {
 					headingStyleFn = (text: string) => this.theme.heading(this.theme.bold(text));
 				}
@@ -445,8 +448,7 @@ export class Markdown implements Component {
 				};
 
 				const headingText = this.renderInlineTokens(token.tokens || [], headingStyleContext);
-				const styledHeading = headingLevel >= 3 ? headingStyleFn(headingPrefix) + headingText : headingText;
-				lines.push(styledHeading);
+				lines.push(headingText);
 				if (nextTokenType && nextTokenType !== "space") {
 					lines.push(""); // Add spacing after headings (unless space token follows)
 				}
diff --git a/packages/tui/test/markdown.test.ts b/packages/tui/test/markdown.test.ts
index c2e2b90d3..8c82fb5f3 100644
--- a/packages/tui/test/markdown.test.ts
+++ b/packages/tui/test/markdown.test.ts
@@ -1032,6 +1032,58 @@ bar`,
 		});
 	});
 
+	describe("Heading levels", () => {
+		it("should render every heading level without a raw # prefix", () => {
+			const markdown = new Markdown("# H1\n## H2\n### H3\n#### H4\n##### H5\n###### H6", 0, 0, defaultMarkdownTheme);
+
+			const plainLines = markdown.render(80).map((line) => line.replace(/\x1b\[[0-9;]*m/g, "").trimEnd());
+
+			for (const heading of ["H1", "H2", "H3", "H4", "H5", "H6"]) {
+				assert.ok(plainLines.includes(heading), `Should render "${heading}" as heading content`);
+			}
+			for (const line of plainLines) {
+				assert.ok(!/^#{1,6} /.test(line), `Raw heading prefix should not render: ${JSON.stringify(line)}`);
+			}
+		});
+
+		it("should taper emphasis with heading depth", () => {
+			const markdown = new Markdown("# h1\n## h2\n### h3\n#### h4\n##### h5\n###### h6", 0, 0, defaultMarkdownTheme);
+
+			const lines = markdown.render(80);
+			const byContent: Record<string, string> = {};
+			for (const line of lines) {
+				const plain = line.replace(/\x1b\[[0-9;]*m/g, "").trimEnd();
+				byContent[plain] = line;
+			}
+
+			assert.ok(byContent.h1.includes("\x1b[4m"), "h1 should be underlined");
+			assert.ok(byContent.h2.includes("\x1b[1m"), "h2 should be bold");
+			assert.ok(byContent.h3.includes("\x1b[1m"), "h3 should be bold");
+			assert.ok(!byContent.h3.includes("\x1b[3m"), "h3 should not be italic");
+			assert.ok(!byContent.h3.includes("\x1b[4m"), "h3 should not be underlined");
+			assert.ok(byContent.h4.includes("\x1b[3m"), "h4 should be italic");
+			assert.ok(byContent.h4.includes("\x1b[1m"), "h4 should keep bold");
+			assert.ok(byContent.h5.includes("\x1b[3m"), "h5 should be italic");
+			assert.ok(byContent.h6.includes("\x1b[3m"), "h6 should be italic");
+		});
+
+		it("should keep deep heading styling across inline code spans", () => {
+			const markdown = new Markdown("##### Deep heading with `code` inside", 0, 0, defaultMarkdownTheme);
+
+			const lines = markdown.render(80);
+			const joinedOutput = lines.join("\n");
+
+			assert.ok(joinedOutput.includes("\x1b[33m"), "Should have yellow for inline code");
+
+			const afterCodeIndex = joinedOutput.indexOf("inside");
+			assert.ok(afterCodeIndex > 0, "Should contain text after inline code");
+
+			const precedingChunk = joinedOutput.slice(Math.max(0, afterCodeIndex - 40), afterCodeIndex);
+			assert.ok(precedingChunk.includes("\x1b[3m"), `Should re-apply italic for h5: ${precedingChunk}`);
+			assert.ok(precedingChunk.includes("\x1b[36m"), `Should re-apply heading color for h5: ${precedingChunk}`);
+		});
+	});
+
 	describe("Strikethrough syntax", () => {
 		it("should render ~~text~~ as strikethrough", () => {
 			const markdown = new Markdown("Use ~~strikethrough~~ here", 0, 0, defaultMarkdownTheme);