Want an easy template for a D&D ice sorcerer? Why not Iceman from the X-Men?
The X-Men originally consisted of five teenagers, who would go on to become the backbone of one of the most popular comic book series of all time. The strongest member of the X-Men (assuming the Phoenix Force isn't counted) is easily Iceman, who has the power to shatter people where they stand by freezing the water in their body. It's possible to create Iceman as a Dungeons & Dragons character, with a little tweaking.
Bobby Drake discovered his mutant powers at a young age, but it took decades to learn just how powerful he was. Iceman is one of the few Omega-level mutants in the Marvel universe, which means he is considered to be as powerful as characters like Magneto and Storm. In his early appearances, Iceman was a joker who threw snowballs at his enemies, but he refined his abilities over time. He was helped by Emma Frost when she possessed his body and used his powers in ways he had never imagined before.
How To Create A Cryomancer In D&D
Iceman's Ability Scores, Subclass, And Background
The main issue with creating Iceman in D&D is that there are currently no cold-based arcane spellcaster classes, but it's very easy to create one. In Plane Shift: Kaladesh, there is a Sorcerous Origin called the Pyromancer, which has a natural control over fire. Simply replace all instances of the class' special abilities dealing fire damage to cold damage and the Pyromancer becomes the Cryomancer.
The version of Iceman we have created uses material from the Player's Handbook and altered content from Plane Shift: Kaladesh mentioned above. Iceman is a human (non-variant) sorcerer who takes on the Cryomancer Sorcerous Origin at level one. Using the basic stat spread listed on page 13 of the Player's Handbook and taking his race into account, Iceman's starting stats would be STR 9, DEX 15, CON 14, INT 13, WIS 11, and CHA 16.
Iceman joined the X-Men at a young age (and was the youngest member of the original lineup). He has spent almost his entire adult life working as a superhero. As such, he would fit the Soldier background. Iceman's starting skills would be Athletics, Deception, Intimidation, and Persuasion. If the variant Feat rules are used, then Iceman would benefit from Elemental Adept (Cold), Resilient, Spell Sniper, and War Caster.
In terms of alignment, Iceman would fall into Chaotic Good. Like the other members of the X-Men, he fights to protect the world that hates and fears him. The X-Men exist outside of the boundaries of the law and are often opposed by the governments of the world, yet they risk their lives to face supervillains and cosmic-level threats whenever they are needed. Iceman has also been a member of other teams, where he has served a similar purpose for the world at large. Iceman is also a prankster at heart, so he would suit the Chaotic end of the spectrum.
Iceman's Spells
Iceman's entire gimmick is that he can lower temperature, allowing him to manipulate ice and transform the environment around him. His spell list would benefit from chill touch, friends, true strike, disguise self, expeditious retreat, fog cloud, mage armor, alter self, blur, enhance ability, enlarge/reduce, gust of wind, gaseous form, haste, protection from energy, sleet storm, slow, ice storm, polymorph, stoneskin, cone of cold, hold monster, globe of invulnerability, move earth, teleport, earthquake, power word stun, and power word kill. There is a lack of cold-based spells in the Player's Handbook, but the DM could be convinced to switch the element of established spells to give Iceman more options, such as burning hands (freezing hands), scorching ray (freezing ray), fireball (iceball), delayed blast fireball (delayed blast iceball), fire storm (ice storm), incendiary cloud (frozen cloud), and meteor swarm (asteroid swarm).
Iceman's character journey has a lot of potential in Dungeons & Dragons, especially as sorcerers are similar to mutants in many ways. He starts out as a light-hearted character, who uses his magic to pull cold-based pranks on friends and enemies alike. Iceman will get serious when the situation demands it, but he doesn't quite grasp the true potential of his power. As he goes on more adventurers and develops his spellcasting ability, he realizes how strong his magic truly is, and it changes him as a result. This could lead to Iceman becoming the full-fledged hero he was always meant to be, even if he can't quite abandon the ice-based puns.
Source: Plane Shift: Kaladesh