Alright, time for the red heroes:
Zane
Combat Proficiency: Excellent. Zane is a bit stronger than the average hero, and he also has haste! Haste gives you a lot more flexibility when setting up Metamorphosis, and often lets you attack a turn earlier than you would be able to otherwise.
Maxband Ability: Zane’s maxband isn’t the strongest, but it’s still useful. The typical counterplay to Metamorphosis is to build a tower and stick big blockers in SQL to try and wear down your heroes. Zane’s maxband lets you shove a big patroller out of the way so that you can attack something with less attack and try and preserve more health on your heroes.
Exhaust Abilities: N/A.
Ultimate Spell: Don’t use this with Metamorphosis.
Other Spells/Abilities: Surprise Attack can help clear your opponent’s patrol zone, or help you get in for additional damage.
Final Verdict: Zane is one of the best heroes with Metamorphosis.
Drakk
Combat Proficiency: Average. Drakk is a 3/4 at maxband with no combat abilities, which is the baseline for a hero.
Maxband Ability: Drakk’s maxband is powerful, but depending on what position you are using Metamorphosis from, you may not be able to use it well. Drakk really wants you to have good units in your deck, and if you went for an early Metamorphosis, you may not have had room to tech good units or time to tech up.
Exhaust Abilities: N/A.
Ultimate Spell: War Drums is a pretty good ultimate, but it wants you to have lots of units, which is hard to do when using Metamorphosis. You probably won’t be able to make this work.
Other Spells/Abilities: If your opponent is trying to stop your heroes with large patrollers in SQL, Kidnapping is good to move those patrollers out of the way and potentially clear most of your opponent’s board.
Final Verdict: Drakk is a powerful hero, but his focus on unit buffs is antisynergistic with the Metamorphosis plan, so he’s a mediocre Metamorphosis partner.
Jaina
Combat Proficiency: Average. Jaina has an extra point of attack compared to the average hero, but also has less health at maxband than any other hero. It’s worth noting that Jaina’s frailty is less of a downside with Metamorphosis than it is normally, because with 5 health she should be able to attack one thing and survive, as long as you can protect her from being attacked.
Maxband Ability: Excellent. Combined with readiness, Jaina’s maxband ability lets her deal significantly more damage than any other hero. Jaina also gets to split her damage between multiple targets, for example by attacking your opponent’s base and exhausting to destroy their tower in combination with another damage source.
Exhaust Abilities: See above.
Ultimate Spell: Jaina’s ultimate spell should win you the game. You can destroy their tower and get an additional base damage, then swing through with Vandy and Jaina for 15, then fetch Dark Pact for 2 more.
Other Spells/Abilities: The other Fire spells all help contribute to a base race.
Final Verdict: Jaina is one of the best heroes with Metamorphosis, because between her maxband and spells, you can destroy the opponent’s base very quickly. You just have to be careful and try and protect her from attacks.