Force of Vigor feels like the right sideboard card against artifacts and enchantments, but I also wanted a multicolor card
Order Scars of Mirrodin now
Any cheap characters that can yield card advantage or ink advantage are high picks in my book
Once stationed, it puts +1/+1 counters or charge counters on targets, or becomes a flying 5/5 that gives your artifacts hexproof and indestructible
This card, once a scourge of Modern, arguably isn't great in Commander - it's just an overstatted vanilla creature, at the end of the day
A sets print run, while not being precisely calculable, naturally ties in with a sets rarity a couple different ways