Insomnia: Cannot be asleep and can't use Rest.
Simple: Its stats are twice as affected by modifiers (Swords Dance raises 4 ATK stages instead of 2, Tail Whip lowers 2 stages instead of 1, etc).
Unaware: During damage calculation, ignores foe's stat changes except SPEED.
Frisk: Upon entering battle, reveal the foe's held item.