[scryfall]Humble Defector[/scryfall] is a card you know can’t be that good, but you just wish you could find a way to use it profitably.
… and maybe there is.
One of the earliest spoilers was [scryfall]Yasova Dragonclaw[/scryfall]. She steals creatures from you opponent. Creatures like those that tap for two cards. There’s also [scryfall]Harness by Force[/scryfall], which is a bit awkward with its double red (but Yasova requires that as well).
So, what else can we do with it? Sacrifice it? Perhaps. There just doesn’t seem to be sacrifice effects in these colors that are usable. I thought [scryfall]Life’s Legacy[/scryfall] would be an option, but no, since its an additional cost, you can’t respond to it by sacrificing the Defector. So, there’s one left: [scryfall]Collateral Damage[/scryfall]. Here you can first use the defector and while its ability is still on the stack, you can sacrifice it.
But these cards don’t make a deck. You probably don’t want to play four [scryfall]Harness by Force[/scryfall]s either. Playing four of a legend is also a bit questionable (although I’m generally very willing to do it, since they are fragile and die anyhow).
How to build on that foundation? It would be good to have more stuff for Collateral Damage to eat. For that reason, we can use [scryfall]Goblin Rabblemaster[/scryfall], which is very strong in its own right. Also, [scryfall]Hordeling Outburst[/scryfall] and, for the late game, [scryfall]Xenagos, the Reveler[/scryfall].
Now the question becomes how can we make those tokens better? Gladly, there’s an answer for this in Fate Reforged. [scryfall]Shaman of the Great Hunt[/scryfall].
What works well with the Shaman? Creatures with evasion… or pseudo-evasion, like deathtouch. Meaning [scryfall]Heir of the Wilds[/scryfall]. Maybe put in one [scryfall]Break Through the Line[/scryfall] as well. Its going to be very strong with [scryfall]Goblin Rabblemaster[/scryfall].
Okay, now I don’t have any clue on whether the curve works at all. We seem to have quite a few three drops, so lets smooth the curve with some [scryfall]Elvish Mystic[/scryfall]s.
4 Elvish Mystic
4 Humble Defector
4 Heir of the Wilds
4 Yasova Dragonclaw
4 Goblin Rabblemaster
4 Shaman of the Great Hunt
4 Collateral Damage
4 Hordeling Outburst
2 Harness by Force
1 Break Through the Line
3 Xenagos, the Reveler
4 Wooded Foothills
4 Temple of Abandon
A few more creatures with power of 4 wouldn’t hurt as they could be very strong with the Shaman.