Thornscape Battlemage
Creature — Elf Wizard
Kicker 
and/or 
(You may pay an additional and/or as you cast this spell.)
When Thornscape Battlemage enters the battlefield, if it was kicked with its kicker, it deals 2 damage to any target.
When Thornscape Battlemage enters the battlefield, if it was kicked with its kicker, destroy target artifact.
Illustrated by
Modern Masters 2017#142UncommonEnglishLegality
Rulings
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.
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.
Kicker costs don’t change a spell’s mana cost or converted mana cost.