I like it for Bolas's Citadel.
First one can move it to the yard for you to trash for treasure it, subsequent copies can remove other ones so you don't hit a 6 mana wall while you try to go off or pull wincons like keyvault or painterstone for you to unearth or whatever.
The fact that this and goblin welder are both goblins really helps with running Cavern of Souls. Before it just wasn't optimal to run 4 Caverns just for Welder in the fear of Derpstep. But with 8 goblins 4 Caverns seems much more viable, and this costing 2 letting it get around d Derpstep is already a plus. How long before Trash 4 Treasure gets restricted lulz
I'm really enjoying this set so far which is full of "What would a Vintage staple look like if we didn't mess up the design the first time."
This is the best example. Costing 2 and having an activated ability of 1 is strong, but reasonable. And Welder, nor the color pie or abilities in general, are meant to just permit exchanges in the opponent's graveyard.
That said, I would have never thought of adding a built-in Entomb, and I think it's great flavor!