(Happy-ish with ev spread atm, but may change before voting still)
Necrozma @ Normalium Z
Ability: Prism Armor
EVs: 252 HP / 180 Def / 76 SpA
Bold Nature
IVs: 0 Atk
- Rest
- Sleep Talk
- Photon Geyser
- Signal Beam
Whole idea of the set is to act as a bulky mon that can rest talk, ala bulky primarina, but utilise Z-Sleep Talk, which raises crit rate by 2, and fires off the z-move that sleep talk was going to use too. So that if/when the mons main checks are gone, it can gain a power boost, and potentially fire off a 140 BP Savage Spin Out / 180 BP Shattered Psyche at the same time. The whole advantage of this over just running psychium-z would be that while you get a randomized z move not the one you want, you retain the crit boost after, giving it some benefit past the single turn, with a 50% chance to crit being akin to a 25% damage boost (half a calm mind) that goes through stat changes and screens/veil, and stopping it from being set up on by calm mind mons (non sub suicune and latias for instance).
One benefit trying to run a rest-talk set with this has over say primarina is prism armour. On a more physically defensive orientated set, with the combination of this and z-move, knock offs, eg from krook can be tanked with ease, as shown below,
252 Atk Krookodile Knock Off vs. 252 HP / 180+ Def Prism Armor Necrozma: 114-135 (28.6 - 33.9%) -- 0.3% chance to 3HKO
Scizor can also only get good 2hkos if running bug bite, or life orb/banded u-turn which isn't a "technical" 2hko due to the forced swap, allowing an easy rest up if not already asleep.,
Bulky Scizor: 0 Atk Scizor U-turn vs. 252 HP / 180+ Def Prism Armor Necrozma: 108-127 (27.1 - 31.9%) -- guaranteed 4HKO
Life Orb Scizor: 252+ Atk Life Orb Scizor U-turn vs. 252 HP / 180+ Def Prism Armor Necrozma: 187-222 (46.9 - 55.7%) -- 75.4% chance to 2HKO
Vs say a latias, this set still has enough special bulk to tank a +1 electrium-z, however it can't tank +1 dragonium-z. However, if deciding to pop z-sleep talk against it, a critting savage spin out is an ohko, and a critting shattered psyche into a signal beam / shattered psyche into a critting signal beam will a guaranteed ko after rocks (technically 99.3- 115.8%, but basically stupidly high chance), noting that crits have a 50% chance, and the crit chance worrks on the z move too since the status z effect rolls first.
Could go on but that was just to demonstrate some ways the set deals with things that by all accounts should be able to do large damage to it. Don't wanna ramble on too much.