Aura Enchanted

Diablo II	Notation	Basic	Class	Skill	Item	Ally	Quest	Area	Monster	Tale

Aura	Level	Minimum Monster Level for Aura Level
Aura	Level	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
Might	max([mlvl/6],1)	4	12	18	24	30	36	42	48	54	60	66	72	78	84	90	96¹⁾
Holy Fire	max([mlvl/6],1)	4	12	18	24	30	36	42	48	54	60	66	72	78	84	90	96¹⁾
Blessed Aim	max([mlvl/5],1)	4	10	15	20	25	30	35	40	45	50	55	60	65	70	75	80	85	90	95
Holy Freeze	max([mlvl/7],1)	4	14	21	28	35	42	49	56	63	70	77	84	91	98¹⁾
Holy Shock	max([mlvl/8],1)		16	24	32	40	48	56	64	72	80	88	96¹⁾
Fanaticism	max([mlvl/8],1)	4	16	24	32	40	48	56	64	72	80	88	96¹⁾
Conviction	max([mlvl/8],1)	4	16	24	32	40	48	56	64	72	80	88	96¹⁾

[1]
¹ such high slvl is obtainable only on Unique monsters in Terror Zones with high enough clvl [2]

Unique supplies an aura randomly selected from those listed above. [3]
Might applies a synergy bonus when Charge is used by an Aura Enchanted Claw Viper or Reanimated Horde (fortunately the same is not true of their minions). [4]
Holy Shock cannot be selected at mlvl <20. [5] [6]
Fanaticism only applies allied +% Damage to Unique, not user +% Damage. [7]
Conviction won't apply to a hostile unit supplying higher level Conviction before Unique Conviction is applied; hostile Conviction won't apply unless it it is equal or greater level. When the unit supplies equal or higher level Conviction after Unique Conviction is applied, Unique Conviction continues to be applied even though the character screen does not display its effects. [8]
When a hostile unit supplies equal level Conviction it will always apply to the Unique... and continue to do so even after the hostile unit stops supplying it. [9] Fixed in D2R. [10]

Reference