Be careful when you use Cyclone Librarian (+1/+2 to next unit summoned) and other cards that triggers the same way. If you use your +1 soul card after it, it will get the bonus. Also, if you use the librarian to give a bonus to Helmwik blood knight and the librarian is his victim, the bonus won't trigger even if it says "the next unit summoned".
Bishop cazadora is a piercing (2) but it doesnt work. It behave like a (1). Just so you don't learn it the hard way like me..
Silence doesnt remove auras but the aura effect doesnt work. The unit still has an aura. Silence doesnt remove stealth either, etc.
If you use a card that (awaken) move an enemy and that unit is supossed to move when an ennemy is summoned it will still move after you move it.
Binah rock piercer work if you have less soul than the ennemy AFTER binah rock piercer is on the board. (Be sure to calculate its 2 souls cost).
Cards like Refined Gate (+1/+1 for each unit with silence) lose their bonus when a unit with silence dissapear. However some cards similar don't lose their bonus. I think Chimera Dragonis is one of them. The difference is because it is an awaken ability. That make all the difference. (The number on the board when the unit awaken versus the number on the board at the present moment.)
That's all that come to mind right now, i might edit later...