I want to be OP. Here are my really bad ideas:

The Blood Gauge: Starts off at 100% instead of 0. Our unique abilities drain the gauge (Quietus, Delirium, Bloodspiller). Every attack we deal add 3 to the gauge. Received attacks increases the gauge by 2. Darkside increases our gauge by 5 every server heartbeat.

Blood Price: Degen effect on our MP that increases our HP regen from our own healing sources by 10% (15% with DA) for 25s.
--Delirium effect: Reduce our Bloodgauge costs bo 10. 180s CD.

Blood Weapon: same as live, but make it usable in Grit to replace the current Blood Price.
--Delirium effect: same as live.

Delirium: Interacts with our abilities in various ways. Activating Delirium is now a buff that is consumed when activating an ability. Costs 40 Bloodgauge.

Living Dead: Snapshot your health at the time you pop it. If Walking Dead triggers, your health fills back up to the snapshot value, however, you suffer a bleed-like degen that cannot be removed or mitigated in any way that removes 8% of your health every second for 20 seconds. Dark Arts Effect: 3% of your HP is removed per second instead of 5%. While Living Dead is active, our body is covered by black and red abyssal energy (like a warriors wrath). While Walking Dead is active make it bright blue and purple. Visual indicators that the effect is up and if it's procced.

Dark Passenger: Twofold attack. The first hit does 180 potency damage. Right behind it is a delayed burst of dark magic that deals 360 potency damage. Same MP cost as live.
--Dark Arts effect: This attack heals you for half the damage dealt.
--Delirium effect: Dark Passenger costs 50 Bloodgauge to use instead of MP.

Grit: Remove it. Bake its effect into Darkside. Increase damage by 10% instead of 20%.

Dark Mind: 20% damage reduction. 60s CD
--Dark Arts effect: 30% damage reduction.
--Delirium effect: Nearby allies gain 10% damage reduction. Damage they mitigate with Dark Mind restores 2% of your max HP per target hit by an attack, lasts 8s.

The Blackest Night: Same as it currently is except for the Bloodgauge restoration when absorbed.
--Dark Arts effect: Double the duration. Immediately restore 50 Bloodgauge on use. Any additional Bloodgauge gained over 100 is lost.
--Delirium effect: Restores 10% of your max health. Allies gain a shield equal to 10% of your maximum HP for half the duration of The Blackest Night.

Shadow Wall: Same as it currently is.
--Dark Arts effect: spread the reduction to all nearby allies within 20 yalms for 4 seconds. This effect also lasts 4 seconds on you.

Quietus: Same as live. Adds 20 potency to the damage per target it hits. (instead of losing potency, like Flare for example, it gains potency instead) 180 base potency.
--Dark Arts effect: Increase Bloodgauge cost to 60, adds 30 potency to the damage per target.

Bloodspiller: Same as live.
--Dark Arts effect: splashes its damage to all nearby targets, dealing half the damage dealt to the first target, 10% less to the second, 20% to the third, and 30% to all remaining targets.

Sole Survivor: Any target you designate becomes another victim and the effect lasts 18s. While the effect is active, you regen 2% of your maximum HP and MP every 3 seconds. If the target dies, you immediately gain the full regen effect as well as filling your Bloodgauge up to 100%.
--Delirium effect: Target yourself in addition to your Sole Survivor.

Souleater: See the OP's suggestion.

Salted Earth: Same as live except it does not fill the Bloodgauge meter.
--Dark Arts effect: This effect becomes a PBAoE that moves with you.
--Delirium effect: Double the duration.