How to unlock Celebi
Getting Celebi means pulling the Johto banner and hitting its 5★ slot. The 5★ band takes 1.5% of all pulls and holds 103 partners, so one specific Celebi works out to about 0.0146% per draw. The 70-pull pity counter guarantees a 5★, but it does not target Celebi specifically, so a guarantee can still resolve to another 5★. A duplicate Celebi refunds 300 coins at the 5★ rate.
Celebi stats and rank
Celebi carries 115 HP, 120 speed, a ×1.25 attack multiplier, ×1.25 physical, ×1.25 special, 100 defense and 100 special defense, 600 in total. On the three-stat percentile this is 78.5 out of 100, which puts Celebi at rank 88 of 966 and in tier A. What separates it from its neighbours is shape, not size: its strongest slot is HP (87th percentile) and its weakest is attack multiplier (63rd percentile), so it spreads its value fairly evenly.
Best moves in Celebi's pool
At move level 5 the pool is led by Petal Blizzard at 33.6 damage per 0.26s (161.7 effective DPS, ×1.25 multiplier), then Body Slam at 75.6 damage per 0.71s (132.6 effective DPS, ×1.25 multiplier), then Tackle at 33.6 damage per 0.38s (112.0 effective DPS, ×1.25 multiplier). 9 of its 20 damaging moves scale with the physical multiplier and 11 with the special one, alongside 4 support moves. Its physical and special multipliers are identical at ×1.25, so the pool decides the build. The top option beats the second by 29.1 DPS, which decides slot one and leaves slot two as a judgement call.
Evolution cards for Celebi
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. That card has to drop inside the run; nothing in the permanent menu replaces it. 20 of its 24 moves carry an evolution card, across 7 distinct cards (Vigor, Sprint, Power, Reflexes, Armor, Magnet and Synthesis). The strongest of them is Petal Blizzard at 161.7 effective DPS, so that is the one worth holding a card for first.
Celebi compared to similar partners
The two closest stat lines in the roster are Mew (+0 HP, +0 speed, same attack multiplier, +0 total) and Jirachi (+0 HP, +0 speed, same attack multiplier, +0 total). Against Mew, the two are level on speed and the two carry an identical ×1.25 attack multiplier, and the rank gap is 1 places. Treat the gaps as the price of the switch rather than free stats, so neither side is a strict upgrade and the move pools have to break the tie.