How to unlock Regigigas
Regigigas is not sold directly, so the only route is the Sinnoh banner, where it occupies a 5★ slot. The 5★ band takes 1.5% of all pulls and holds 103 partners, so one specific Regigigas works out to about 0.0146% per draw. The 70-pull pity counter guarantees a 5★, but it does not target Regigigas specifically, so a guarantee can still resolve to another 5★. A duplicate Regigigas refunds 300 coins at the 5★ rate.
Regigigas stats and rank
Regigigas reads 120 HP, 120 speed, ×1.58 attack, ×1.58 physical, ×1.14 special, 110 defense and 110 special defense, for a 670 base-stat total. On the three-stat percentile this is 92.8 out of 100, which puts Regigigas at rank 7 of 966 and in tier S. The relative picture matters more than the total: its strongest slot is physical multiplier (100th percentile) and its weakest is special multiplier (64th percentile), so it is a specialist rather than an all-rounder.
Best moves in Regigigas's pool
At move level 5 the pool is led by Body Slam at 75.6 damage per 0.71s (167.6 effective DPS, ×1.58 multiplier), then Tackle at 33.6 damage per 0.38s (141.6 effective DPS, ×1.58 multiplier), then Quick Attack at 44.8 damage per 0.56s (125.8 effective DPS, ×1.58 multiplier). 5 of its 7 damaging moves scale with the physical multiplier and 2 with the special one, alongside 4 support moves. Its physical multiplier is the higher of the two (×1.58 against ×1.14), so physical moves convert better. The top option beats the second by 26.1 DPS, which decides slot one and leaves slot two as a judgement call. That DPS figure says nothing about range or behaviour, so treat it as a first filter rather than a final ranking.
Evolution cards for Regigigas
Its starting move, Tackle, evolves into Take Down once the move is at level 5 and you hold the Vigor card, which boosts HP for that run. That card has to drop inside the run; nothing in the permanent menu replaces it. 7 of its 11 moves carry an evolution card, across 5 distinct cards (Vigor, Sprint, Power, Reflexes and Armor). The strongest of them is Body Slam at 167.6 effective DPS, so that is the one worth holding a card for first.
Regigigas compared to similar partners
The two closest stat lines in the roster are Koraidon (-5 HP, +15 speed, -0.14 attack, +0 total) and Baxcalibur (+2 HP, -5 speed, -0.08 attack, -70 total). Against Koraidon, Koraidon is 15 speed faster and Regigigas hits harder by ×0.14, 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.