Had a rare oops with this today, my 4x Spirit Fox vs a level 1 bombot. I went to cast my first fox as the traits were going but before I could target the Cursed trait killed off the bombot! Had to close the game since I got stuck.
Also, I like Fox x3 + Myzmer, as Myzmer gives 5 magic to each. If you cast before traits finish you don't get the bonus from Myzmer. This is also applicable in a Elspeth, Bombot, hero, troglodyte build. If you cast the empowered Elspeth on trog before his traits go off you lose his +5 to Bombots stats.