Guide or encyclopedia or anything

[Karol13]

Usually the game works great on providing information by right clicking (holding longer on mobile phone)

But for example - when I am promoted, I am given two specializations:
Moonlight Sentinel
Spell Singer

And although both sound great, I would like to see some attributes behind them. (Like when I decide what unit should choose what path during level-up based on the abilties, damage, resistances... of the next tier promotion units)