My first post here so plz be kind! (i.e. not sure if this build is new, apologies if someone has previously posted the same approach) .
The recent plat sale has let me test a freeze/sigils based build that is capable of soloing 150 Wyverns with minimal use of respots (respots will be needed if freeze is avoided or fails or is interrupted).
The build (based on my current mage which is level 146):
Lure fire 23/30
(+ other lures as required for bossing, grouping etc)
Approx 500 health sigils, and 300 energy sigils.
Approx 2100 hps, 2700 energy.
Fire magic 1860
Ice magic 1660
Fire resistance 670
(Willpower, Vigour, Reflex 600+)
All dia armor except feet which are frozen celestial (dia needed for +focus).
Royal Shield of the Mountain (for armor, elemental and other protections).
Dia Cane (for +200 fire and ice magic).
Heroic Ammy + Revenant bracelets.
Rings Royal e-shield, Grand e-shield, flame and Lure fire.
(Only one 'hard' to get item used, the 'Flaming Charm of the Lich')
Turn off auto-attack (no autos used for this method).
E-well, fireshield, e-shield, then e-boost.
Start fight with fire lure. Cycle firebolt until e-shield drops.
When e-shield drops, wait until hps are approx half, then use first freeze for a 14 second pause.
During pause refresh e-boost, fireshield, lure fire (wait until end of freeze for sigils do their work) .
When freeze drops, cycle firebolts and re-freeze as soon as possible.
During the second freeze, refresh e-shield, e-boost and e-well (wait until end of freeze for sigils do their work).
Goto Start (repeat until wyvern is dead).
Notes: I found that the Fire magic 1860, and Ice magnet 1660 are needed to reduce spell failures to acceptable level. The same build can be used for helping with other bosses - remove dia cane and shield,and go h2h with Golden Blade of Fire, also swap out dia hat and gloves for Golden Helm of Intensity and Heroic Haste gloves.