Trap doesn't need to be level 3, its point is to stop enemy unit movement. Slow is also already quite good at level 2, it doesn't really need to be level 3.
Each school has good points for going to level 3:
- Chaos is cool level 3 to get mass weakness, doom level 3 (target level 4), Sheep level 3 (target level 4), Necro Call level 3, and sacrifice level 3.
- Distortion is cool level 3 to get mass Magic Shackles, Phantom level 3, Hypnosis level 3 and mass Haste if you want use it.
- Order is cool level 3 to get Mass bless, Resurrection level 3 (target level 4), Mass Battle cry, Gift level 3 (target level 5), Helplessness level 3, eventually mass demon and dragon slayer.
In impossible mode and if you try to do a record that changes a lot the game, I'm trying play this mode but I don't know which one I would prefer.
Without an attempt to try a record so no time pressure the decision is tough. If I need choose only one the choice is difficult:
- I'd be tempted to go Distortion level 3 just to get Mass Magic Shackles.
- But on another way Order level 3 for level 3 for Resurrection, mass bless, mass battle cry and even Gift level 3 is very tempting.
- Chaos level 3 is less tempting for me but still is just because of Sacrifice and Sheep level 3.