<button id="summonBtn">召喚！</button>
<div id="stage"></div>
const btn = document.querySelector('#summonBtn');
const stage = document.querySelector('#stage');
count=0
btn.addEventListener('click', function() {
count=count+1
const spirit = document.createElement('p');
spirit.textContent = count+' 体目のそーが現れた！';
stage.appendChild(spirit);
});