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

anime.timeline({loop: loopvalue})
  .add({
    targets: '.theselector .letter',
    translateY: [100,0],
    translateZ: 0,
    opacity: [0,1],
    easing: "easeOutExpo",
    duration: 1400,
    delay: (el, i) => 300 + 30 * i
  });