Low to the ground aggro-control combining synergistic, cheap creatures that grow in size alongside disruption spells.
CREATURES:
Usher of the Fallen - 2 power 1 drop Warrior that we can put mana in to create human tokens.
Ascendant Spirit - starts as a 1/1 for 1 but can grow at instant speed with excess mana.
Archpriest of Iona - 1/2 Human Cleric for 1 by itself, grows rapidly with other party creatures and can be a 5/2 flying creature for 1.
Luminarch Aspirant - 1/1 Human Cleric for 2, adds a counter every turn, very good tempo creature on turn 2. Still good later on.
Brazen Borrower -3/1 rogue flying for 3. Also doubles as removal.
Linvala, Shield of Sea Gate 3/3 wizard for 3. Keeps other creatures alive, can detain any nonland permanent every turn with party.
Faceless Haven - Counts as every creature type, helps fill in the gaps to activate party bonuses.
SPELLS
The mix of humans and non-humans in blue and white allows the deck to make full use of Fight as One as an offensive or defensive combat trick and to reliably only pay one mana for Of One Mind. Party creatures also enable Concerted Defense to function as a one mana Negate for anything you can't deal with otherwise.
24 lands is a lot for a deck with such a low curve, but a tempo deck can't afford to miss land drops and there are some good mana sinks with Faceless Haven, Ascendant Spirit and Usher of the Fallen.