Jack Bright (back side) Dr
Ral Zarek is most comparable to Ajani Vengeant, who is arguably the third best planeswalker ever after Jace, the Mind Sculptor and Elspeth, Knight-Errant
Lets set up with the basics: When you get to the this slot in a Collector Booster, youre going to get a Showcase (In this set, thats the Monster Manual), Borderless, or Extended-Art treatment in foil
Make sure every deck you build packs a good amount of artifact removal, and try to include one or two cards which destroy all artifacts (Shattering Spree, Akromas Vengeance, Aura Shards)
Id have said 3 mana for an enchantment that draws a card a turn might be a little slow for todays Magic, but given that the Arena is pretty popular on, well, Arena, maybe theres some legs here after all