Nature for Power Split Araquinid

Was toying around with this and was just curious what some people opinions are, specifically on the nature I should be going with.

Araquinid:
Bold Nature
EV: Def 252, Sp Def 252, Hp 6
Item: ?? Leftovers maybe?
Power Split
Lunge/Leech Life
Liquidation
Unsure (Poison Jab? Crunch? Subsitute? Aqua Ring?)

So the plan is to have Att and Sp Att as low as possible (hence the nature) and then when you use Power Split it reduces the opponents Att and Sp Att as much as possible while giving yourself the modest boost, Lunge to then further lower the ooponent's attack, MAYBE Leech Life for the HP Recovery, Liquidation for the chance at lowering defence while my defense stats are boosted as much as possible with the nature and EVs because I will be slow so I need to withstand as much as possible. Also STAB. Haven't decided on the last move yet, going to try various things and see what works.

ANYWAY, not looking for better movesets or this that or the other because there are certainly better movesets, just wondering what opinion was on this specific nature and if I should consider another because while the Bold nature reduces the opponent's attack stat more, I also don't get as much of a boost to my own attack either when the numbers are averaged. Also wouldn't mind opinions on what the fourth move should be. Thank you!

EDIT: Also, FYI, I'm currently in the process of breeding Dewpiders right now, so if anyone wants a Power Split Dewpider (With or without it's Water Absorb Hidden Ability, I'm breeding both at the moment) shoot me a PM and I'll send you one.

Which ability are you planning on running on this one, Water Bubble or Water Absorb?

If you still want to boost Defense but not lower your Attack, you could use a Relaxed nature, Araquanid's Speed is pretty bad to begin with. Not sure what you'd actually want to go with, since it varies depending on what Pokemon Araquanid is facing at any given time. It may want the extra Def for some, the extra Atk for others.

In that last slot you may want to run Leech Life to help keep its health up while doing this--sounds like(some) battles could be slow and so that could help it last longer. Toxic could be useful as well.

?\_(?)_/?

Stockpile may also be an option, just make sure to get rid of any Toxic users (Water Bubble takes care of burns).

Z-Stockpile or Rest could be used to fully heal.

Maybe:

Araquanid @ Normalium-Z
Calm
Water Bubble
252 HP / 252 Def / 4 SpD
- Power Trick
- Stockpile
- Scald
- Leech Life/Poison Jab/Toxic

The EV's could and probably should use more work.

I would definitely be going with Water Bubble for sure, and WOW! I didn't know Z Stockpile healed HP! That certainly changes a lot of what I was planning!

I was actually trying to get the Att as low as possible with the nature so that power split would reduce the opponents Att that much more, but yeah, both of these posts give me a lot to think about, thank you very much for the advice, this gives me a tone to think about! I wasn't even going to bother with Stockpile but knowing it's Z move does that, it's definitely a big consideration!