Cheapest priced copy (Ravnica Allegiance): $0.99 at Card Kingdom, near mint, their price list as of .
Dovin, Grand Arbiter 
Legendary Planeswalker — Dovin · Mythic · Crimson Vow Commander · #153
+1: Until end of turn, whenever a creature you control deals combat damage to a player, put a loyalty counter on Dovin.
−1: Create a 1/1 colorless Thopter artifact creature token with flying. You gain 1 life.
−7: Look at the top ten cards of your library. Put three of them into your hand and the rest on the bottom of your library in a random order.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.99 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ravnica Allegiance | 167 | Mythic | $0.99 | $2.49 |
| Crimson Vow Commander | 153 | Mythic | $0.99 | — |
2 rulings from Wizards of the Coast
- 25 January 2019The delayed triggered ability created by Dovin's first ability triggers for each creature you control that deals combat damage to a player this turn. Dovin gets only one loyalty counter as each ability resolves, no matter how much damage was dealt.
- 25 January 2019If you have fewer than ten cards in your library as Dovin's last ability resolves, look at however many cards you have, put three of them into your hand (or all of them if you have fewer than three cards in your library), and then put the rest back in a random order.