If you are a paladin or dragon-hunter it becomes a sword that has no stat requirement, whether it is one-handed or two-handed depends on which skill is higher than the other when you go to upgrade it at a shrine of beliar.
the shrine takes max-hp (permanently) to upgrade its damage output and chance of its spell effect going off.
I'll copy and paste the handy table made by N3Burgener from gamefaqs
Code:
Player Claw 1H Crit 2H Crit Deducted
Level Level Dmg % Dmg % HP
-------------------------------------------------------
<11 1 90 12 100 12 -5
11 2 91 14 101 14 -10
13 3 92 16 102 16 -15
15 4 93 18 103 18 -20
17 5 94 20 104 20 -25
19 6 95 22 105 22 -30
21 7 96 24 106 24 -35
23 8 97 26 107 26 -40
25 9 98 28 108 28 -45
27 10 99 30 109 30 -50
29 11 100 32 110 32 -55
31 12 101 34 111 34 -60
33 13 102 36 112 36 -65
35 14 103 38 113 38 -70
37 15 104 40 114 40 -75
39 16 105 42 115 42 -80
41 17 106 44 116 44 -85
43 18 107 46 117 46 -90
45 19 108 48 118 48 -95
47 20 110 50 120 50 -100
One of the awesome things about the claw is that if you are an archer and neglected raising your strength you can still use the claw of beliar and tis magical effect (which at max level has a 50% chance of going off) ALWAYS does 100 damage guaranteed (it bypasses all armor/resistance), so even enemies like Black Trolls can theoretically go down in 5 hits.
The downside is that it won't work on the end-boss.
It is the best 1-handed weapon in terms of damage output, but is statistically inferior to the Berserker axe as a 2-handed weapon if,and only if, you have your 2-handed skill at 100%. If it is only 80% or so then I'd say that it is still the best weapon in the game (at max level, of course).
If you are a mage then you do not get the sword but instead get access to some unique spell runes that you can exchange for one another (you can only have one at a time, but can exchange them at the shrine). the final rune is the single most powerful spell in the game but also drains a minimum of 250(+all remaining) mana, so there's even a good chance you wont' have enough mana to cast the fucking thing.
Otherwise they're "eh" spells -- table below:
Code:
Circle: HP/Total HP: Spells:
Circle 1: -5/-5 HP Root Snare
Circle 2: -5/-10 HP Steal Energy
Circle 3: -5/-15 HP Beliar's Wrath, Create Guardian
Circle 4: -5/-20 HP Insect Swarm, Create Zombie
Circle 5: -5/-25 HP Cry of the Dead
You can only carry one Beliar Rune at a time, and must pray at a Shrine of
Beliar in order to exchange it for another one. It does not cost any extra HP
reduction to do so.
