How to unlock Yanmega
There is no direct purchase for Yanmega. It appears on the Sinnoh banner inside the 4★ pool. The 4★ band takes 6.5% of all pulls and holds 211 partners, so one specific Yanmega works out to about 0.0308% per draw. The 70-pull pity counter only applies to 5★ results, so Yanmega has no floor of its own and no targeted pull. A duplicate Yanmega refunds 120 coins at the 4★ rate.
Yanmega stats and rank
The sheet lists Yanmega at 109 HP, 118 speed, ×1.34 attack, ×1.12 physical and ×1.34 special, with 86 defense and 56 special defense — 515 base-stat total. On the three-stat percentile this is 79.8 out of 100, which puts Yanmega at rank 77 of 966 and in tier A. Relative standing explains more than the total here: its strongest slot is special multiplier (91st percentile) and its weakest is special defense (36th percentile), so it is a specialist rather than an all-rounder.
Best moves in Yanmega's pool
At move level 5 the pool is led by Gust at 31.2 damage per 0.26s (161.0 effective DPS, ×1.34 multiplier), then Body Slam at 75.6 damage per 0.71s (118.8 effective DPS, ×1.12 multiplier), then Tackle at 33.6 damage per 0.38s (100.4 effective DPS, ×1.12 multiplier). 10 of its 17 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 (×1.34 against ×1.12), so special moves convert better. The top option beats the second by 42.1 DPS, which decides slot one and leaves slot two as a judgement call.
Evolution cards for Yanmega
Its starting move, Bug Bite, evolves into X-Scissor once the move is at level 5 and you hold the Power card, which boosts attack for that run. The permanent menu cannot substitute: only a Power card picked during the run unlocks the evolution. 17 of its 21 moves carry an evolution card, across 6 distinct cards (Vigor, Sprint, Power, Reflexes, Armor and Synthesis). The strongest of them is Gust at 161.0 effective DPS, so that is the one worth holding a card for first.
Yanmega compared to similar partners
The two closest stat lines in the roster are Sandy Shocks (-1 HP, +2 speed, +0.03 attack, +55 total) and Zapdos (+1 HP, +2 speed, +0.05 attack, +65 total). Against Sandy Shocks, Sandy Shocks is 2 speed faster and Sandy Shocks hits harder by ×0.03, and the rank gap is 16 places. Every one of those numbers cuts both ways, so the decision is about which stat the run needs, so neither side is a strict upgrade and the move pools have to break the tie.