Honestly, as a Nasus main myself. I personally take stacking CDR runes relying more on being able to last hit as this allowed me to build more armor and other defensive runes without losing stacks. I think about it this way, if you take more dmg from enemy laner its harder to cs thus u lose stacks, so even if u have 10-20% flat cdr u can not safely stack and farm without dying easily. That's mainly why I go the stacking overtime cdr as it allows a safer laning and more consistent stacks.
However, as this is an old thread, riot just released most of the new runes, and I think the new grasp will be the best as you can gain lots of healing and defense from healing(and as Nasus has the passive lifesteal) you will be able to constantly proc the runes throughout laning which makes it harder to bully him out of lane. But the BEST part? You can sub rune into inspiration and get the 5% CDR and Max CDR rune. Before you couldnt do this if you went grasp, but now you can so this seems to be the best imo for him. I mean really look at the healing you get, here ill list it quick.
-Grasp: Healing ever 4 seconds bonus dmg on auto plus inc max health permanently
-Font: it bond of stone but you can heal from it with reduced healing tho, either this or a 60sec 375+20% max hp tower hit depending on lane.
-Ironskin or Mirror Shell: Say hello to one of the best runes xD: whenever u heal for 20 hp, gain 3% armor or 3% MR. Mind you nasus innate lifesteal xD. u also gain 3 armor or mr. The other rune is late game inc to stats 3 more armor and mr, BUT if you really play nasus you know that laning phase early most important. Contrary to some, Nasus is MID GAME CHAMP, late game the amount of resistances/pen items/team fights makes it way easier for you to die before even getting close to hitting a squishy for 1k dmg.
-Lastly: I think all of the last 3 are optional depending, I personally would go second wind, which heals you for 4% missing hp after taking dmg from champ, good against lane bullies, especially ranged ones. Another one grants inc. max hp every 10 minion kills BUT thats late game and so won't help u much early. The other is just windspeakers without the mr and armor inc with a little more heal for low hp champs. More of support rune tho. Pretty much other two are the ones you will go for. Max hp prob against tanks, while second wind for harder lanes.
Now u can do sub tree: Inspiration is go to for 5% cdr. haven't really messed with other runes but this one was key to nasus before, so should be the same in new meta hopefully.
-Definitely the 5% good cdr rune
-Second, mostly up to you, there's one that keep giving free empowered biscuit every 3 minutes that inc max mana and heal based on MISSING HP. Pretty good against lane bullies. The lender might also be really good but got to see it in action, getting earlier CDR items could be a huge boon, like the sheen power spike.
Thats my take on the runes atm, to sum it up, before you couldn't go grasp and get the cdr rune. Now u can, inc. laning power against lane bullies that Nasus struggles against, and remember, gives stacking health from grasp plus so far good passive healing and resistances that will scale to late game.
One Last Note: I do see you can do a couple more cdr options if you spec into sorcery, however, you will be extremely weak hp and armor wise. It's a riskier rune set but u will get a sortve stormraiders that now procs on 3 unique atks hitting, and 15% cdr at level 10. Mind u, 10% is given at level 10, so you really would be playing a dangerous game relying on your ability to stack well and limit damage taken, cause you wont have resistances until you get your defensive items so lvl6+.
Lol this is long, Nasus mains 4 ever xD*[slayer-pantheon-thumbs]*
