I've always wanted to play the Skirnir archetype but it's horribly written and doesn't really function all to well untill after most games are finished.
I've worked a little around with it's abilities and wanted to share my rework with your for advice and discussion.
Skirnir (Archetype)
Diminished Spellcasting: A skirnir casts one fewer spell of each level than normal. If this reduces the number to 0, he may cast spells of that level only if his Intelligence allows bonus spells of that level.
Sorcerous Shield (Ex): At 1st level, skirnirs are proficient with all types of shields, including tower shields, and do not suffer an arcane spell failure chance when casting magus spells while using a shield. They treat their magus levels as their fighter levels for the purpose of qualifying for shield-related feats. This ability replaces spell combat.
Arcane Bond (Su): At 1st level, a skirnir gains a shield (except for a tower shield) as an arcane bond item. This is identical to the wizard class ability, but the skirnir may only bond with a shield, not a familiar or other item.
Arcane Pool: At 1st level, a skirnir can use his arcane pool to grant an enhancement bonus to a weapon as normal, as well as to his shield, paying the arcane pool cost separately for each. At 5th level and above, he can also add the following shield special abilities: animated, arrow catching, arrow deflection, bashing, blinding, fortification(any), reflecting, spell resistance (any).
Spellstrike (Su): At 1st level, a skirnir may use this ability with a weapon or shield bash attack. He may also use a touch attack or shield bash with his shield in conjunction with any pool strike magus arcana.
Shielded Spell Combat (Su): At 4th level, a skirnir gains the spell combat ability, but only when wielding his bonded shield. A skirnir may use his shield hand to perform somatic components for magus spells. At 10th level, he gains the benefits of improved spell combat. At 16th level, he gains the benefit of greater spell combat.
This ability replaces spell recall, improved spell combat, and greater spell combat.
Spellshield (Su): At 7th level, as a standard action, a skirnir may store a magus spell in his shield by spending 1 point from his arcane pool per level of the spell. This functions as the spell storing weapon special ability, but activates only on a successful shield bash by the skirnir and is not limited to spells of 3rd level or less. This ability replaces knowledge pool.
Greater Spellshield (Su): At 16th level, a skirnir may activate a stored spell as an immediate action after being struck in combat. He may choose to have the spell affect himself or the creature that struck him. This ability replaces counterstrike.