VampHPDrain

async function wait(ms) {return new Promise(resolve => {setTimeout(resolve, ms);});}
if(args[0].hitTargets.length === 0) return {};
let tokenD = canvas.tokens.get(args[0].tokenId);
let actorD = game.actors.get(args[0].actor._id);
let target  = canvas.tokens.get(args[0].hitTargets[0].id);
let itemD = args[0].item;
let gameRound = game.combat ? game.combat.round : 0;

const diceMult = args[0].isCritical ? 2: 1;
const numDice = 3 * diceMult;
args[0].isCritical ? numDice * 2 : numDice;
let damageRoll = new Roll(`${numDice}d6`).roll();
new MidiQOL.DamageOnlyWorkflow(actorD, tokenD, damageRoll.total, "necrotic", [target], damageRoll, {flavor: "Necrotic Bite - Damage Roll (Necrotic)", damageList: args[0].damageList, itemCardId: args[0].itemCardId });
await MidiQOL.applyTokenDamage([{damage: damageRoll.total, type: "healing"}], damageRoll.total, new Set([tokenD]), itemD.name, new Set());
const effectData = {
 label : "Drain",
 icon : "icons/skills/wounds/blood-drip-droplet-red.webp",
 origin: args[0].uuid,
 changes: [{
   "key": "data.attributes.hp.max",
   "value": `-${damageRoll.total}`,
   "mode": 2,
  "priority": 20
   }],
  disabled: false,
  duration: {seconds: 86400,startRound: gameRound, startTime: game.time.worldTime},
}
await MidiQOL.socket().executeAsGM("createEffects", {actorUuid: target.actor.uuid, effects: [effectData]});
let hpNow = target.actor.data.data.attributes.hp.max;
let updateHP = hpNow - damageRoll.total;
let the_message = `<p>${tokenD.name} drains ${target.name} of ${damageRoll.total} pts from their maximum Hit Point value!</p><p>${target.name} now has Maximum Hit Point maximum of ${updateHP}.</p><br><p><b>If it reaches O, they die!!</b></p><br><p> ${tokenD.name} regains ${damageRoll.total} Hit Points back!</p>`;
await wait(600);
ChatMessage.create({
      user: game.user._id,
      speaker: ChatMessage.getSpeaker({actorD: actorD}),
      content: the_message,
      type: CONST.CHAT_MESSAGE_TYPES.EMOTE
    });