Grimwar has to hit face immediately or it can be pinged off for little to no cost in most matches- in the normal course of dealing damage to you, which is what the opponent wants to do anyway and will lose them no tempo. Your general takes the recoil from any hits you dish out, and your general has to be in range of your target (the enemy general, often) necessitating that decks which want to make full use of Grimwar must use tracers.
Crescendo on the other hand cannot be pinged off and thus must be removed via either dispel or hard removal (rarer than say, any spells, abilities, or minions available that can hit your general’s face, and it costs your opponent tempo since removal doesn’t help them by dealing damage to your face). Crescendo also cares nothing about recoil, generally giving enough health to its target to sponge any hits. Crescendo is easy to use to trade into an enemy minion you need to remove that would be disastrous for your general to attack directly, and it will still easily threaten lethal after being used for removal.
– TL;DR Overall Crescendo is harder for your enemy to deal with and more versatile, at the cost of 2 damage, which in the grand scheme of things is not relevant because often your general can attack and kill a minion on that turn anyway which they wouldn’t have done with Grimwar, thus evening out the score.
As for nightsorrow vs lure, anything nightsorrow can destroy, lure can move off into a corner where it might never be relevant again. Futhermore, anything nightsorrow can’t destroy (read: most things) lure can still move off into a corner where it might never be relevant again. This is particularly useful for things you don’t want to kill completely- like Aymara’s and Taygetes, two very common threats you have no good answers to right now (lightbender is a loss in temo for those purposes, and leaves behind big bodies). This makes lure better. Also, as a side note, using a nightsorrow to kill an egg is a huge loss in tempo and probably almost never a good play-- but you could do it with lure for one mana less anyway. Lure is so amazing that if you desperately don’t want to cut out nightsorrow I’d suggest you cut ritual banishing or dark transformation because it’s a travesty not to have lure.
Shadow dancer does deal damage, but the things you could be playing instead of it will deal much much more damage, such as vorpal reaver, which you realllllly should have in a swarm deck as it’s hands-down the best swarm-enabler in Abyssian, but in any case 9 moons or Kron also are more dangerous too. It’s not that dancer is bad, it’s that everything it does is done better by something else-- vorpal is more damage, crescendo is a better deathwatch, kelaino heals better. I wouldn’t use a deck slot on dancer.
but nether summoning is really good, especially with ritual banishing.
