Why no Kolaghan's Command? It's really good. Maybe 2 command and 1 electrolyze? or just 3 command. Adding this means you might not need 2 Vandalblast in sideboard, and maybe just a Shatterstorm instead. I recommend Izzet Staticaster in the sideboard, it is so insane against a lot of decks. Rise/Fall is good too, but that's more in the controlling versions of Grixis, not sure about grixis delver.

What matchups are you having trouble with?

downie78 So... I don't know why I'm not running Izzet Staticaster in my sideboard, especially considering I have multiple copies just sitting around collecting dust. I want to run Shatterstorm over Vandalblast in my sideboard, however, I don't have any copies right now. I'm gearing up to order a bunch of cards, and I'm planning on getting a few copies of it.

In terms of Rise/Fall, I'm not in love with the card. I get that it's good, but I prefer it in a more controlling deck, and even there I don't think it's incredible. I run Grixis Control as well, and don't have any copies of it in that deck. As for Kolaghan's Command, I run two copies in the sideboard of Grixis Control, and should probably run 1-2 copies in this deck. I do prefer Electrolyze in this deck because it cantrips, which is important to ensure that I have things to do.

yeah fair points, and I guess in grixis control you're bringing back bigger threats like Jace, Vryn's Prodigy  ^Flip and Pia and Kiran Nalaar which makes Rise/Fall better. As for electrolyze vs k-command. K-command basically cantrips as well, since you're often either getting a creature back from your graveyard or making them discard a card which can be relevant. It is especially gross with Snapcaster.

Is Rakdos Charm mainly for twin decks? If so, Rending Volley might be a better option, being uncounterable.

Rakdos Charm is mainly for Twin but it has random applications against decks that take advantage of their graveyard as well as decks with dangerous Artifacts, like Affinity, so I like having that more than Rending Volley.

I'm not sure why you have 4 Young Pyromancers. Maybe cut 1 or 2 and add some gurmag anglers?