Munitions Expert When you're playing goblin tribal, you need to build up a mass of creatures, and therefore you really want to limit the number of cards you run that aren't goblins
Generally, ST11-001-uta players pick one of these as their big threat in the deck: OP04-031-donquixote-doflamingo, OP06-118-roronoa-zoro, OP01-051-eustasscaptainkid-701, P-061-monkeydluffy, and OP06-035-hody-jones
Amethyst/Ruby can be useful for control decks focused on maintaining sway over the board, while a good Emerald/Steel build tends to angle for weakening an opponent by depleting their resources through discard abilities
It might still be better to make it bigger
Alternative full art cards have been around since Pokmon TCGs Sun & Moon era, but the cards released under those sets were all alternate versions of GX cards