Are you sure about that? Already tested after the update?
yes, if u want runecaster go for cryo 3 freezeing sphere is not worth it imo 
Solo PVE Contents, except ET I think.
Regular Map is very easy now, so I assume you are talking solo 290 Dungeon or Saalus.
I’ve few suggestions and some variant in each of them.
Elementalist as Core
Main > Wiz3-Elem3-Warlock2
The cookie-cutter build, with using 2H Staff you are squishy a bit, need stack def/mdef up 2.5k to decent soloing. Good Rotation of strong Skills but very squishy. Like murmillo, any build that relying on skill rotation need a lot of $ to up attribute and upgrade weapon.
Variant 1 > Wiz3-Elem3-RC-Warlock
If you like Meteor, this build Emphasize on Warlock Mastema’s debuff for 100% holy damage, then using Rune of Justice 2OH holy elements to deal 555k damage on bosses. If you like to play as caster.
Variant 2 > Wiz3-Elem3-RC-Sage
In a false impression that Sage is red icon and dps class, hope Sage C2 will really mean for it.
Just like Warlock C2 have major upgrade from C1.
Thauma as Core
Main > Wiz1-Pyro2-Thaum3-Warlock2
It looks strange supportive thauma as DPS class? Oddly, it is a Midas Touch class that can turn some weak skills into a decent skills (wiz3/pyro2/cryo-kino), turning decent skills into a devastating skills (warlock2). Emphasize on Shrink Monsters and Triple Chibi Swells can make all skills even lv15 energy bolt become viable. It is a class that compatible with any role/party but need daino scroll, atk? def? cc? debuff? you have it all.
Tips: If you want further polishing, utilize ChappyCards/Cure/PoA scroll will allow you kill dungeon boss 10-20s.
Variant 1 > Wiz3-Thaum3-Warlock2
More for PvP or party with Falconer, energy bolt fast casting good for PvP, and Magic Missile is super strong with Falconer. Compare Pyro2 a bit slower in DG290
Variant 2 > Wiz1-Cryo1-Psycho1-Thaum3-Warlock2
Against of large group of mobs? kill them off with your cryo-psyho combo, then leaving a bunch of evil spirits on the ground. Everything will die in the land that full of landmines.
Why not elem3thaum2? we never know what in R9, but i’m sure elem3thaum3 will not better than thaum3warlock3, at the same time we not sure elem3-thaum2-xx is good or not.
Sorcerer as Core
Main > Wiz1-Cryo3-Socerer2-X-X
If you like summoner, let pets fight for you, then go for this. This build pretty easy to gear up and only need decent riding attribute and powerful weapon to up on track.
Any variant will fine
I think in Rank9 Cryo3-Socerer2-Necro3 is good build, but yet we have wait for R9 to be safe.
These 3 builds are able to full Solo DG290 so far, with cost efficient Sorc>Thauma>Elementalist