Stone Sheath

Skill details

Full: For 10...30 seconds, attacks made by target foe and all nearby foes deal earth damage and cannot cause a critical hit.

Concise: Also hexes foes near target (10...30 seconds). Converts attacks to earth damage and removes ability to land critical hits.

Earth Magic	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21
Duration	10	12	13	15	17	18	20	22	23	25	27	28	30	32	33	35	37	38	40	42	43	45

Acquisition[]

Could be used in conjunction with Ward Against Elements, Elemental Resistance, Mantra of Earth, or Geomancer's Armor to reduce damage taken from attacks. Mantra of Earth would also provide energy per hit.
Using this on Assassin-type foes will render their Critical Strikes useless and deprive them of the energy gain bonus they receive when making Critical hits, thus making them far less dangerous (if their primary damage dealing ability relies on standard Dagger Attack Skills).
In combination with the Ranger Spirit Winter and skilled use of this spell on all foes who attack (mainly) with weapons, one could cause next to all damage dealt to become Cold Damage. This as an alternative to using the Ranger Elite Spirit of Greater Conflagration with Winter in combination, which almost has the same effect. In such a case, Cold Resisting skills and equipment will be useful, like Ward Against Elements, Elemental Resistance, Mantra of Frost, Frostbound Armor, or Hydromancer's Armor.