Greetings Etherealians, today I'm going to break down the various relics to help you decide what will suite your needs.
SPP = Stat Per Point, exclusively a metric to determine your damage and/or accuracy increase per point. This is not necessarily a metric to determine what is best, aside from purely how "cost effective" a Relic is. Also does not account for damage reductions as 99% of the time in Runescape DPS is the name of the game, tankiness is a very niche requirement.
PM = Perk Metric, a completely subjective 1-10 scoring on how good its perk effect is. If there is no effect aside from modifying the Relic's stats, it is given a zero.
Arbalist:
Cost: 150
Accuracy: +25%
Damage: +25%
CROSSBOWS ONLY
SPP: 0.333
PM: 0
Unholy Ranger:
Cost: 75
Accuracy: +100%
Damage: +0%
PRAYER MUST BE AT ZERO
SPP: 1.333
PM = 0
Quick Spitter:
Cost: 75
Accuracy: +0%
Damage: +0%
SPP: 0
PM = 1
Arrow Shredding:
Cost: 100
Accuracy: +0%
Damage: +1%
SPP: 0.01
PM = 0
Armadylean Decree:
Cost: 75
Accuracy: +25%
Damage: +25%
SPP: 0.666
PM = 0
Spiked Shield:
Cost: 150
Accuracy: +20%
Damage: +20%
SPP: 0.266
PM = 0
Wild Magic:
Cost: 150
Accuracy: +0%
Damage: +5%
SPP: 0.033
PM = 0
Unholy Wizard:
Cost: 75
Accuracy: +100%
Damage: +0%
PRAYER MUST BE AT ZERO
SPP: 1.333
PM = 0
Hyper Vengeance:
Cost: 50
Accuracy: +0%
Damage: +0%
SPP: 0
PM = 5
Pest Tamer:
Cost: 75
Accuracy: +5% (Melee/Range)
Damage: +5/6.25% (Melee/Range/Elite)
Accuracy: +22.5% (Magic)
Damage: +0/1.25% (Magic/Elite)
SPP: 0.133 (Melee/Range)
SPP: 0.15 (Melee/Range/Elite)
SPP: 0.3 (Magic)
SPP: 0.316 (Magic/Elite)
PM = 2
The Reaper:
Cost: 100
Accuracy: +10%
Damage: +10%
OFF SLAYER ONLY
SPP: 0.2
PM = 0
Power of the Gods:
Cost: 100
Accuracy: +0%
Damage: +0%
SPP: 0
PM = 4
Bandosian Might:
Cost: 75
Accuracy: +0%
Damage: +10%
MELEE WEAPON MUST BE >4 TICK ATTACK SPEED
SPP: 0.133
PM = 0
Unholy Berserker:
Cost: 75
Accuracy: +0%
Damage: +100%
SPP: 1.333
PM = 0
Bloodthirster:
Cost: 150
Accuracy: +0%
Damage: +0%
SPP: 0
PM = 10
Plunderer:
Cost: 100
Accuracy: +0%
Damage: +0%
SPP: 0
PM = 1
Tank Role:
Cost: 150
Accuracy: +0%
Damage: +0%
Damage Taken: -75%
IN COX/TOB ONLY
SPP: 0
PM = 0
Tank Mastery:
Cost: 100
Accuracy: +0%
Damage: -25%
Damage Taken: -50%
SPP: -0.25
PM = 0