I like the idea you have here; it reminds me of how I designed my mummy/rt/SoR deck, so that one pendulum turn 1 is all you need to get SN -> mummy -> RT -> SoR spam on turn 2 (with death mark) much like how this deck you have will do the same, only it is turn 1 pend, turn 2 SN -> scorpion -> unstoppable -> shards/whatever. Anyway, I mention this because, given my experience with that very similar deck (in terms of quanta curve) I think that 7 pendulum is excessive. You only really need 1 to run the entire deck, and starting with 2+ pends in hand doesn't help at all except maybe SN -> SoB if you played second. I'd cut 2 pendulums for other stuff, maybe an extra scorp/unstoppable, maybe more shards of sacrifice, or whatever you think is best. With the mulligan, I don't think I've ever had a 0 pend start with that deck at 5 pendulums in 30 cards.