Squirtle

One of the "starter" Pokemon that players can catch when they start Go, Squirtle's line has more of an uphill battle than its compatriots. Lower overall offensive output holds Blastoise back a fair bit, though it's still perfectly viable and can overcome its limitations as Mega Blastoise. Just note that it's best to wait for an event to bring back Hydro Cannon before evolving, because that move is an outright requirement for viability!