Use the wp_die_handler to alter your frontend dead

die-in-beauty.php

<?php
	/**
	 * Plugin Name: Schöner Sterben mit wp_die()
	 * Plugin Author: David Remer/Websupporter
	 **/

	add_filter( 'wp_die_handler', 'die_in_beauty_filter' );
	function die_in_beauty_filter( $die_handler ) {
		if ( is_admin() ) {
			return $die_handler;
		}
		return 'die_in_beauty';
	}

	function die_in_beauty(  $message, $title, $args ) {
		get_header();
		if ( empty( $title ) ) {
			$title = 'Ein Fehler ist aufgetreten';
		}
		?>
			<div id="primary" class="content-area">
				<main id="main" class="site-main" role="main">
					<article class="error">
						<header class="entry-header">
							<h1><?php echo $title; ?></h1>
						</header>
						<div class="entry-content">
							<?php echo apply_filters( 'the_content', $message ); ?>
						</div>
						<footer class="entry-footer">
							<p style="text-align:center;font-size:6rem;">😲</p>
						</footer>
					</article>
				</main>
			</div>
		<?php
		get_sidebar();
		get_footer();
		die();
	}
?>