How to unlock Necrozma
Getting Necrozma means pulling the Alola banner and hitting its 5★ slot. The 5★ band takes 1.5% of all pulls and holds 103 partners, so one specific Necrozma works out to about 0.0146% per draw. The 70-pull pity counter guarantees a 5★, but it does not target Necrozma specifically, so a guarantee can still resolve to another 5★. A duplicate Necrozma refunds 300 coins at the 5★ rate.
Necrozma stats and rank
Necrozma carries 114 HP, 111 speed, a ×1.4 attack multiplier, ×1.29 physical, ×1.4 special, 101 defense and 89 special defense, 600 in total. On the three-stat percentile this is 80.2 out of 100, which puts Necrozma at rank 73 of 966 and in tier S. What separates it from its neighbours is shape, not size: its strongest slot is special multiplier (95th percentile) and its weakest is speed (64th percentile), so it is a specialist rather than an all-rounder.
Best moves in Necrozma's pool
At move level 5 the pool is led by Body Slam at 75.6 damage per 0.71s (136.9 effective DPS, ×1.29 multiplier), then Tackle at 33.6 damage per 0.38s (115.6 effective DPS, ×1.29 multiplier), then Quick Attack at 44.8 damage per 0.56s (102.7 effective DPS, ×1.29 multiplier). 6 of its 13 damaging moves scale with the physical multiplier and 7 with the special one, alongside 4 support moves. Its special multiplier is the higher of the two (×1.4 against ×1.29), so special moves convert better. The top option beats the second by 21.3 DPS, which decides slot one and leaves slot two as a judgement call.
Evolution cards for Necrozma
Its starting move, Confusion, evolves into Psyshock once the move is at level 5 and you hold the Reflexes card, which boosts cooldown for that run. Menu upgrades use a separate system and never stand in for Reflexes. 13 of its 17 moves carry an evolution card, across 6 distinct cards (Vigor, Sprint, Power, Reflexes, Armor and Magnet). The strongest of them is Body Slam at 136.9 effective DPS, so that is the one worth holding a card for first.
Necrozma compared to similar partners
The two closest stat lines in the roster are Volcanion (-8 HP, -4 speed, +0.02 attack, +0 total) and Heatran (-3 HP, -1 speed, +0.02 attack, +0 total). Against Volcanion, Necrozma is 4 speed faster and Volcanion hits harder by ×0.02, and the rank gap is 106 places. Read those deltas as swap costs, because a gain on one line is usually paid for on another, so neither side is a strict upgrade and the move pools have to break the tie.