Arena-like UX (animations/sounds/etc)

Arena has some awful flaws like it's grind to get rares, addictive features like daily wins and lack of fun features like commander.

But what it does well is UX. Beginners to Magic can learn the game quickly via MtG: Arena since it has many cues like varying sound effects depending on power of creature attacking, unique particle effects for different types of playable exiled cards, sound effects for various cards played, etc.

These all make for a more entertaining experience and makes it easier to tell at a glance or listen what is going on, without having to rely on a text log telling you what happened in a turn.

These examples and others would be superb for attracting people put off by the existing UX such as myself. I'd be willing to contribute to a bounty towards these kinds of features if there's interest in it on the dev side.