Guild Raid Buffs for Maestro

⭐⭐⭐
25% more magic damage against the hands: great for Augustus or Amira.

Mandatory
Almost every team dies without this buff (at high level). Note that it destroys the horn any time you switch to the astral plane.

⭐⭐
25% more pure damage against the hands: good for Heidi I guess?

⭐⭐⭐⭐
50% more pet power (for the pet's team skills). Great for Albus, good for Merlin or Axel.

⭐⭐⭐
50% more pet patronage power (for the pet's patronage skills and bonuses). Probably not game-changing, but it may be team-specific. Maybe Oliver needs this to keep some heroes alive?

⭐⭐⭐
6% to 18% more healing at the start of the astral phase. May be necessary to survive the astral phase.

⭐⭐⭐
A physical team will gain a few percents of damage.

By the time you can leave the material plane, you would be at 86% to 77% damage reduction, rather than 95% (it takes 16s for Maestro's barrier to normally go from 20% to 100%). The impact is even stronger with At the Speed of Light.

You could also use it to stay on the material plane a bit longer, albeit it is probably not good.

⭐⭐⭐
It lets you silence the horn sooner, and we will all thank you for that.

⭐⭐⭐⭐⭐
Applying five debuffs over 13s to the harp is impossible for many teams, so this is greatly impactful for many of them. Albeit I do not know which ones benefit the most from it.

⭐⭐
You will gain a few percents of healing during the astral phase, which may just be what you need to survive.

By the time you can leave the astral plane, you would be at 86% to 77% healing reduction, rather than 95% (it takes 16s for Maestro's barrier to normally go from 20% to 100%). The impact is even stronger with At the Speed of Light.

You could also use it to stay on the astral plane a bit longer.

⭐⭐⭐
More energy, good.

⭐⭐
Up to 30% damage reduction at the start of the astral plane, this may help a bit to survive this phase.

⭐⭐
95% damage reduction when entering the material world. Sounds nice, but you will be fully healed by this moment.

⭐⭐⭐⭐⭐
Another big heal at the moment you enter the material phase. With this buff and Keepers of Balance, most teams will be full heal.

Depends
Great for Cornelius, good for physical teams in general, because they deal most of their damage at the start of the material phase.

This phase normally starts with a small barrier (20%), which this buff reduces, providing a 6% to 19% bonus damage to Cornelius.

⭐⭐⭐⭐
It lets you build physical teams without healers. Mandatory for Cornelius.

⭐⭐⭐⭐⭐
It lets you cycle faster, reducing the impact of the barrier (dmg reduction) and requiem (healing reduction), and granting you big heals with Keepers of Balance.

⭐⭐⭐⭐
5% to 15% more healing at the start of the material phase. It will cover Keepers of Balance and Power over Life, and in manual mode you can trigger your ults at this moment.

⭐⭐⭐⭐
10% to 30% more speed anytime you silence this despicable horn? Yes!

Depends
Useless for most teams, yet a game changer for those that can apply 2-5 debuffs over 13s but only to the wrong targets (Maestro is the front enemy).

Explanation: to kill the harp you need to apply 2-5 debuffs in 13s, or your stats progressively lower to zero over the course of the fight. Every 13s the harp rejuvenates and your stats do not reset until you finally put debuffs fast enough.

⭐⭐
Retribution deals low damage anyway, so what is the point? It can even be useful sometimes, for example to charge Isaac in the Cornelius team.