so what to spend exp on?

[Lost Question]

just beat the corrupted tree for the first time and im wondering what I should focus on spend ing exp on? as far as base stats go mine are
energy:
50 speed
30 power
750k
30 bars

mana:
50 speed
10 power
250k
10 bars

adventure stats:
284 power
306 toughness
1412 hp
20/s regen

other exp purchases: inv. spaces max, basic loot filter, extra accessory, auto merge, recycling 60%, item daycare.

[Fel]

Never spend exp on adventure stats (not sure if you did but it needs to be said).
You want to spend your exp mostly in energy and magic stats, if possible roughly similar amount of exp spent on each entry (outside of speed since it caps at 50 anyway).

This is pretty much the guide line you will follow as far as exp goes and you will continue like that at least until the end of the second difficulty (adding the third resource to the mix at some point of course).

When you are roughly ready to jump to a higher difficulty, spending on the attack and defense multiplier for a bit will help you start off that next difficulty a lot more easily but that's about it.

[Trim]

Training Auto Advance is a great quality of life -- lets you dump a bunch of energy into Basic Training at the start of each run and will auto allocate excess energy when each new tier unlocks. Each rebirth will require less manual effort to actively watch your training levels and perform energy allocation.

I concur with Fel above: Since you've picked up most everything that's useful, base energy & magic power / cap / bars are the bread and butter of the game. The more you invest there, [almost] every other system mechanic gets faster or more efficient. These will be your main focus most of the time -- everything else you can purchase with exp is a secondary concern.

More recycling is good if it's available. And once you hit the required energy cap, you can pick up the first Yggd fruit auto-activate (initiates fruit growth automatically, though you still have to harvest / eat them yourself). As diggers & beards unlock, you'll probably want to pick them up pretty quickly, too.

Don't bother with adventure stats for a loooooong while. Exp isn't exactly easy to come by at that stage of the game, and the benefits are paltry for the cost. I've had the game running for nearly four months now, and on the couple occasions where I dumped exp on adventure stats I have always regretted it.