humm a instant skill, the idea can be good but you have problems with mechanic
to be "skip" can't be a passive skill, (because is optional choice)
a text can be better "when Earth Giant come into play destroy target shield" however similars creatures have been made in the past.
use pulverand be happy...
1. Earth Giant automatically skips attack to destroy opponent shield
if opponent have shield.
Earth Giant behaves individually and "skips" automatically,
you cant control Earth Giant,
even if you dun want Earth Giant to skip attack to destroy shield,
Earth Giant will still skip attack to destroy shield if opponent have a shield.
Rather than a skill, i would call it a passive ability, thats why i made it cant be lobomotized.
Pulverizer is awesome,
just clearing misconceptions of Earth Giant.