Click the Join the crowd tab on the edge of the video. Twitch asks you to share your identity once, so your companion can follow you from stream to stream.

Then type any Minecraft name: your companion wears that skin. Use your own, or any skin you like; you can change it later.

On a phone the same features are in the MasuCompanion panel below the stream in the Twitch app.

Most of the time MasuCompanion is just two small tabs on the edge of the video:

• Your profile tab: your level and Masurium, with the crowd meter as a thin line along the bottom. Hover it for the meter and the jackpot; click it for your profile.
• Your spotlight tab: your chance of a seat in the next squad, or your controls once you are in it.

Short moments (rewards, loot bursts, results) pop up beside the tabs for a few seconds. Everything waits for your stream delay, so it lines up with what you see on the video.

Every few minutes while the vault timer runs, a vote opens with three fates. Each one is a real Vault Hunters modifier that lands on the streamer's vault for a while:

• Blessings help the streamer.
• Curses make the vault harder.
• Chaos is just weird.

The streamer picks a spice before each run: Chill offers 2 blessings and a mild curse, Spicy one of each, Chaos a strong curse. Click an option or press 1 2 3; you can change your vote until it closes. Nobody sees the split until the end, then the winner hits the vault.

Some options show ×1–2 or ×1–3: when they win, the vault rolls how many copies land, and the copies add up (Tailwind ×3 stacks three speed boosts). Higher counts are rarer, except on Chaos, where every count is equally likely. Options marked Instant are crowd moments that happen on the spot: Freeze Frame, Coin Rain, Launch or Shrink Ray.

When an effect ends, a line beside your tabs says what it did, like “Coin Explosion ×2 · 14 coins dropped”.

Your vote weighs a little more the higher your level: 1x at level 1, up to 2x at level 50.

The crowd meter fills from everyone watching, voting and grabbing gems, plus Bits, subs, hype trains and channel point rewards. You see it as the line under your profile tab.

When it is full, chat gets 20 seconds to vote on an ultimate: a big, short vault effect like more champions or kills that rain coins, or an instant crowd cast such as Champion Call (nearby mobs become champions worth a loot burst), Crowd Nova or Totem Drop. Ultimates that stack roll every count evenly. When it fires, the viewers who charged the meter most get a shoutout on the stream.

Your calls show beside your tabs when the timer starts and again when the run ends, with what you won.

When nobody called the right answer, that question's stakes go into the channel's jackpot, and so does half the value of the loot gems nobody grabs. At the end of the stream the streamer rolls it in game and one viewer wins all of it. Every question you staked on since the last roll gives you one chance; how much you staked does not matter. Your overlay tells you your chances during the roll and whether you won.

Each run, three viewers join the streamer in the vault as little allies wearing their own skins, names and titles. They never fight and mobs ignore them.

• One MVP seat goes to the best engagement score of the last run: voting, watching, calling predictions right.
• Two lucky draws pick from everyone active in the last 10 minutes. Every run you watch without a seat raises your chance, and so does a good score. Bits and subs do not buy seats.
• After a seat you rest for two runs, so everyone gets a turn.

Your spotlight tab always shows your chance for the next squad. When the streamer enters the portal room, the squad is revealed on the stream and your tab tells you if it is you.

While you are in the squad, your spotlight tab opens your controls:

• Signature ability: your pick from level 5: Heal Burst, Shield Bubble, Mana Spring, Frost Guard, Shockwave or Cooldown Kick. Your ally walks into the streamer's view and casts it, and the overlay says what it did. Each shows how often it is ready (every 90 seconds by default, the crowd-control ones a bit longer), and a cast that would do nothing, like a heal at full health or a Frost Guard with no mob near, is held back and gives you the cooldown back.
• Emotes: your ally walks into the streamer's view and waves, cheers or dances, with an optional speech bubble.

More emotes and phrases unlock on the reward track and in the shop.

Where the streamer turned chat commands on, you can play without opening the overlay:

Votes never get a reply, so chat stays readable.