Probably Brightstone Ritual or Battle Hymn. How were you finding those effects? You already have a really low curve so I feel like these wouldn't be that useful. Skirk Fire Marshal looks like another good addition

WhichKing, I took a mountain out of the deck and put Skirk Fire Marshal in. Forgot about him and my curve is low enough to play 34 mountains instead of 35.

Brightstone Ritual and Battle Hymn seem a bit underwhelming at first, that I can understand. But, in my experience Krenko, Mob Boss always get a ton of hate when he is on the table. Since mono red doesnt have a ton of mana ramp, these 2 cards are pretty much helping me cast krenko again and again and again...

Any other cards? :)

Haha.. 34 mountains is a little bit too low for me, the lowest I'd go is 36 to be honest, but if your playgroup allows unlimited free mulligans I guess it wouldn't be too problematic to run less than 36 lands.

Regarding the one-shot mana ritual cards... I guess you could try running Sword of the Animist to "ramp" lens instead.

WhichKing I think I even played with less. The curve is that low that with 4 mana im pretty much good to go. The deck has one goal being able to cast krenko a few times. Even tho I loooove sword of the animist (I play it in my Karlov's Will deck). I think it's too slow for krenko, the one time mana jumps often provide the mana to cast krenko again. Most of the time he is removed by spot removal, so the rest of the goblins survive. But maybe i should give it a go, see how it works out.