Thornscape Battlemage

If you put a permanent with a kicker ability onto the battlefield without casting it, you can't kick it.

If a spell's kicker cost was paid, the spell is "kicked."

Kicker costs don't change a spell's mana cost or mana value.

You can pay any particular kicker cost only once. You can't pay it multiple times to get multiples of either triggered ability.

If Thornscape Battlemage is put onto the battlefield as the result of a spell or ability, there's no opportunity to kick it.

You choose whether to kick a spell as you cast it, and you pay that much along with the spell's mana cost at the same time. Kicking a spell is always optional.