Infernal Grasp isn't a synergy piece by any means, but it's one of the best Doom Blade variants ever printed
She protects your other enchantment creatures with powerful keywords and, at the end of your turn, can return an enchantment creature from your graveyard directly to the battlefield
Being able to make an opponent sacrifice a creature can, on turn two or three, leave them with nothing to attack with, helping her stick around for longer
Its 'All For One' ability also grants other Musketeers an extra point of Strength
As long as there are no blockers on your opponents side or other flying creatures, the now 22/22 dragon can take a player out with commander damage
With all sorts of powerful options ready to choose from you might be a bit overwhelmed with all the cards at your disposal