var textWrapper = document.querySelector('.theselector .letters');
textWrapper.innerHTML = textWrapper.textContent.replace(/\S/g, "<span class='letter'>$&</span>");

anime.timeline({loop: loopvalue})
  .add({
    targets: '.theselector .letter',
    scale: [0, 1],
    duration: 1500,
    elasticity: 600,
    delay: (el, i) => 45 * (i+1)
  });