You must have both permanents on the battlefield, and Estrid, the Masked needs to have at least two loyalty counters or more
Pikachu EX is a four-star rarity card so if you are using it you won't be able to complete the Battle Tasks that require only 1, 2, or 3 Rarity
During this, you do everything else play cards as resources (ink), play other cards after paying the ink cost, use their abilities, or gain victory points
But if your goal is simply to own a stunning Mew card without spending almost $1,000, Crown Zeniths Mew GG10 is one of the best-value singles the Pokmon TCG has to offer
Discard it from the hand while your graveyard is empty and any card sent to the grave will be banished instead