Yo dawg, I heard you like Fluid templates...

<?php

class Tx_Myext_ViewHelpers_FluidViewHelper extends Tx_Fluid_Core_ViewHelper_AbstractViewHelper {

    /**
     * @var Tx_Extbase_Object_ObjectManagerInterface
     */
    protected $objectManager;

    /**
     * @param Tx_Extbase_Object_ObjectManagerInterface $objectManager
     */
    public function injectObjectManager(Tx_Extbase_Object_ObjectManagerInterface $objectManager) {
        $this->objectManager = $objectManager;
    }

    /**
     * @return string
     */
    public function render() {
        $source = $this->renderChildren();
        $source = html_entity_decode($source);
        /** @var Tx_Fluid_View_StandaloneView $view */
        $view = $this->objectManager->create('Tx_Fluid_View_StandaloneView');
        $view->assignMultiple($this->templateVariableContainer->getAll());
        $view->setTemplateSource($source);
        $rendered = $view->render();
        return $rendered;
    }

}