In addition to what the above guy said:
Full Con is for survivability, a few months ago before the rank9 update Cryo3 Chrono3 sage1 had virtually no damage output so they had no reason to invest in int. Currently though the last 2 ranks can give you access to a whole lot of variation in builds so stats will vary depending on what you choose.
Cryo3-chrono3 can pick the following last 2 ranks:
Enchanter2 -> Turns your auto attack into lightning bolts which synergize with cryo’s freeze damage attribute and also chrono’s attack speed buff. Also gives you access to two more buffs enchant lightning which adds lightning damage for your entire party and enchant earth which gives all party members an additional chance to block even without shields. You can go full int or full dex with this build (full dex only if you have good ping).
Sage2 -> Gives you access to the buff “missile hole” and also has some more gimmicky support effects through micro dimension’s duplicate attribute (can duplicate stuff like inquisitor’s breaking wheel and some other stuff) and ultimate dimension’s expand magic circle attribute. Has three high cooldown offensive spells that do decent damage, and will benefit a lot from chrono’s pass. Probably best to go full int with this build, or full con if you can invest on a really strong weapon.
sorc1-sage1 -> This is the new full support, you only take sage1 for missile hole, and you take sorc1 for the summon servant skill which will give your party even more useful buffs like adding AoE attack ratio (lets your party hit more things with most attacks) and reduced SP regen ticks (zealots with blind faith will love you for this). If you invest on a weapon, a good devil type card and go full SPR your sorc summoning skill can also provide a good chunk of dps.
sorc2 -> This will turn you into a hybrid summoner-rider. You still get an additional support skill through summon servant, but being able to ride your summon will give you access to a few more interesting skills and AoE attacks. You’ll need to invest on a weapon, a devil type card for summoning and full SPR to get the most out of it.
EDIT: There’s also a different support type class path you can take, namely the ones that revolve around thaumaturge 3. Thaum3 support is more desirable for less geared parties, a Cryo3-Chrono3 support is what heavily geared people prefer though.