That sounds like a card formulation problem. And you should try to solve the root cause instead of trying out workarounds. You can read on card creation here:
You can do it using a little JS:
<div id="reveal" data-full="{{Back}}"></div>
<script>
(function(){
const el = document.getElementById("reveal");
const message = el.dataset.full;
let i = 0;
// clear any raw output so nothing shows until JS runs
el.textContent = "";
const interval = setInterval(() => {
if (i < message.length) {
el.textContent += message[i++];
} else {
clearInterval(interval);
}
}, 200); // 200 ms per character; bump up to slow it down
})();
</script>
You can also use a hint field in the front of your cards, see Field Replacements - Anki Manual.