It particularly synergizes well with this decks commander, the Sliver Gravemother, as once she is around you can copy legendary slivers and not lose them to the legend rule
Haven of the Spirit Dragon is a Land with Dragon Tribal synergy and by paying , and sacrrificing it, it can return a Dragon from our graveyard to our hand
That said, this card is so outright powerful that leaving white at home is definitely worth it
A possible leaves trigger, three possible enters triggers, three possible death/leaves triggers from the tokens, another possible enters trigger if Siegebreaker dies or leaves the field and your exiled creature comes back, and it can be combined into blink combos and burn combos by itself
Sower of Temptation is both a faerie and a Mind Control effect
Below are a few examples of fillers, but if you would like to see a complete list of most known fillers check them out here