A big ol' session that i MAY have lost the question to.
So a bard of space probably inst the best space player out there, not too bad but not good being a destroyer class. A thief of time is controversial too as it can go either way. I don't see many conflicts within the team so its good in that respect. Also, although I don't think its been specifically said to be the case but I think lords and muses are specifically two player sessions but who knows.
Anyway...
The sylph of breath would be able to create freedom for other people, giving them more choice over what they can do. He could possibly heal injuries using the wind too.
The prince of void would be able to destroy nothing, meaning he would be good for uncovering secrets of filling people in on information along with being one of the main fighters of the group.
The knight of rage would be able to exploit rage making enemies make mistakes or using her own rage as a power source going into a berserker mode, making her one of the better fighters.
The mage of mind would know how people think and act on it, very useful in battle. She would also be a very smart, logical person, good at solving puzzles.
The heir of blood would passively get everyone to work together and to their best abilities. She would probably be good as the leader of the group as she would keep everyone in a team.
The seer of doom would have it worse than Sollux in visions of everyone's fate, knowing all of them. However, unlike Sollux people would believe him and he would be able to help guide people towards their best fate.
The lord of life from my understanding would have all the active classes powers over life meaning he would be able to create, destroy, edit, use, know about and exploit it. Basically he could do anything from being a healer to a tank to a hard hitter and would be very adaptable.
The rogue of hope would be able to redistribute hope to everyone, keeping them all hopeful and giving them all potential and belief in themselves.
The maid of heart would create heart for herself, making her more instinctive and empathetic, essential acting oppositely to the mage. This would still give her higher fighting ability though.
The thief of time would steal time for herself and might cause some issues timeline wise but should be able to fix them.
The page of light would allow everyone to exploit light meaning his planet would probably have alot of loot and information that anyone can get and use whenever they want.
Finally, the bard of space would let space get destroyed so unless the genesis frog is well protected, there is a high chance of losing. He probably wouldn't want to have to breed frogs much either.
Altogether i don't see to much of a reason your session would fail other than a bit of riskiness with the bard, lord and rogue.