56 cards where the set is “j25” and it’s legal in Pioneer and it’s not legal in Explorer

Abandon Reason (Foundations Jumpstart #513)
Advocate of the Beast (Foundations Jumpstart #622)
Ainok Artillerist (Foundations Jumpstart #624)
Ainok Guide (Foundations Jumpstart #625)
Akroan Crusader (Foundations Jumpstart #515)
Akroan Skyguard (Foundations Jumpstart #159)
Archaeomancer (Foundations Jumpstart #285)
Arena Athlete (Foundations Jumpstart #518)
Aven Reedstalker (Foundations Jumpstart #287)
Banisher Priest (Foundations Jumpstart #169)
Brimaz, King of Oreskos (Foundations Jumpstart #58)
Chosen by Heliod (Foundations Jumpstart #181)
Coat with Venom (Foundations Jumpstart #412)
Coordinated Assault (Foundations Jumpstart #532)
Divine Favor (Foundations Jumpstart #191)
Elite Skirmisher (Foundations Jumpstart #193)
Emberhorn Minotaur (Foundations Jumpstart #540)
Expedition Raptor (Foundations Jumpstart #194)
Experimental Aviator (Foundations Jumpstart #309)
Felidar Sovereign (Foundations Jumpstart #198)
Garruk, Caller of Beasts (Foundations Jumpstart #659)
Garruk's Packleader (Foundations Jumpstart #660)
Gnawing Zombie (Foundations Jumpstart #446)
Goblin Rabblemaster (Foundations Jumpstart #558)
Godsend (Foundations Jumpstart #204)
Graveblade Marauder (Foundations Jumpstart #451)
Grave Strength (Foundations Jumpstart #450)
Ivy Lane Denizen (Foundations Jumpstart #674)
Kapsho Kitefins (Foundations Jumpstart #318)
Killing Glare (Foundations Jumpstart #120)
Militant Inquisitor (Foundations Jumpstart #226)
Murasa Ranger (Foundations Jumpstart #691)
Nantuko Husk (Foundations Jumpstart #468)
Necropolis Regent (Foundations Jumpstart #469)
Ojutai Exemplars (Foundations Jumpstart #232)
Opportunity (Foundations Jumpstart #338)
Overwhelm (Foundations Jumpstart #697)
Pharika's Chosen (Foundations Jumpstart #474)
Read the Bones (Foundations Jumpstart #479)
Relief Captain (Foundations Jumpstart #241)
Retreat to Kazandu (Foundations Jumpstart #707)
Satyr Hoplite (Foundations Jumpstart #595)
Shoulder to Shoulder (Foundations Jumpstart #254)
Snapping Gnarlid (Foundations Jumpstart #714)
Stone Haven Outfitter (Foundations Jumpstart #263)
Sungrace Pegasus (Foundations Jumpstart #265)
Tenacity (Foundations Jumpstart #104)
Tethmos High Priest (Foundations Jumpstart #271)
Time to Feed (Foundations Jumpstart #727)
Triplicate Spirits (Foundations Jumpstart #273)
Trueheart Twins (Foundations Jumpstart #605)
Ukud Cobra (Foundations Jumpstart #498)
Ulcerate (Foundations Jumpstart #499)
Undergrowth Champion (Foundations Jumpstart #736)
Voldaren Duelist (Foundations Jumpstart #612)
Wingsteed Rider (Foundations Jumpstart #279)

Though this query has ended, its relics still slumber in New Argive.