1. More PvP Content
PvP as of right now is the most straight-forward PvP in a game I have ever seen in my life. Click a button. Find an opponent. Fight against the opponent using the deck you built beforehand. There is no type of surprising aspect or twist in PvP to give any kind of excitement to the player whatsoever. On top of that, the meta-game of Elements is fairly predictable due to the lack of updates and therefore, PvP (in my opinion) as become a predictable and boring atmosphere. I personally can't stand this. We need some time of new PvP innovation. My suggestion is that similar to For Fun and For Glory (SSB4), we make PvP 1 a serious atmosphere with no restrictions for those players that just want to PvP legitimately with no extra drawbacks (For Glory) and we make PvP 2 a more "lighthearted" atmosphere by adding daily twists to the meta-game, similar to the weekly tourney. For example, on one day, duels in PvP 2 could be limited to decks that carry six or less pillars. Players would be forced to adjust their deckbuilding to play in PvP 2, varying the meta-game drastically. This would be a type of change in the PvP system that Elements could use right now in my opinion.
2. PvP Duel Features
Currently, PvP Duel is just PvP 2 without rewards. We should be able to do more in PvP Duel. Right after we find an opponent, in my opinion, we should be brought to a menu where we can change the settings of the duel (including the health of both players, mark power, draw speed, deck size limit (30-60), banned cards, etc.). This would allow people to actually mess around with duels.
I would even go so far as to say we should include a feature in PvP Duels that allow both players to set which cards come out on which draw. With this, bad draws won't make the difference in the outcome of the game. An entirely new dynamic to the game would be added. What part of your strategy did you make come out first? Did your strategy counter your opponent's strategy when his came out? Maybe you pack all of your creatures into the first ten draws, but your opponent packed all of his CC into the first ten draws. It'd be a completely new story if you could determine which cards came out on which draws. We need features like this in PvP Duel.
3. More Quests
The starting quests are okay, but I'd just like more quests in general. More quests gives me something to do rather than waste my time idly grinding AI. More of an opportunity to get cards that I would normally have to wait for the oracle to give me. Just adds something new to the game.
4. RPG Elements
Basically, Elements just needs new content in my opinion, and giving it aspects of an RPG isn't such a bad idea. It'd be a new view on Elements and a new system altogether. It wouldn't be a bad thing for those people just starting the game and veterans would probably be able to get used to the game fairly quickly. A stats system and leveling up sound pretty good to me.
5. GUI Improvements/ Visual Changes
Elements hasn't changed its theme one bit since it first came out. It's gotta go. A new font or color or something. It's gotta go.