You adjust your pet's temperament by giving commands during battles. Sometimes it can take several battles before it changes. Overall, depending on what temperament you started with, it may take a number of battles before you adjust to it to what you want.
You can check your pet's temperament by talking to the left NPC of the two NPCs that are to the right of the cage. The temperament stated by the match announcer is not as specific.
For tameness:
Code:
Extremely wild
Very wild
Wild
Somewhat wild ^ Don't think, kill! & Less thinking, more striking!
Somewhat tame v Watch your opponent, then attack. & Think, think again!
Tame
Very Tame
Extremely Tame
For aggressive:
Code:
Extremely defensive
Very defensive
Defensive
Somewhat Defensive ^ Guard, block, parry, hold! & Back off a bit!
Somewhat Aggressive v Give 'em more bite! & Show no Mercy!
Aggressive
Very Aggressive
Extremely Aggressive
The commands I listed above are meant to illustrate what direction certain commands will move your pet's temperament. (ex. Give 'em more bite! & Show no Mercy! move toward more aggressive)
For sidestepping and/or a sleep nuker you want:
Somewhat tame, tame, or very tame
--with---
somewhat aggressive or aggressive