Arena will focus on Standard, whereas Magic Online will focus on older formats like Modern, Legacy, Vintage, Cube, etc
It may have brought success to the play-type, but it was hated by many for feeling unsportsmanlike and grinding for any player stuck on the other end of it - never mind the effect it had on the pacing of tournaments taking place during its brief reign
[[Thirst for Discovery]] is probably the next best depending on the format and your deck construction
Weakness / Resistance / Retreat Cost: P+10 / / 1 Product Details Card Number / Rarity: 090/130 / Common Card Type / HP / Stage: Psychic / 40 / Basic Card Text:Pok-POWER Baby Evolution Once during your turn (before your attack) , you may put Mr
Also, all shadowless cards are 1 st editions, and they packaging that they come in is also considered shadowless, which you can determine through some slight differences, such as Charizards wings on the booster box
And if you play lots of MTG Arena, consider downloading Draftsims add-on, Arena Tutor