Summoner

Within the school of conjuration exists a specific usage of that school, magic used to create entities for the purpose of fighting for you. A summoner develops techniques for enhancing the creatures they create and fighting with them. 

Summoning Savant

Beginning when you select this school at 2nd level, the gold and time you must spend to copy a spell with the Summoning tag into your spellbook is divided by 4. Additionally all spells with the Summoning tag are considered part of the wizards spell list for you.

Lingering Summons

At 2nd level all creatures that you create with a spell (not including ones that turn things into creatures such as giant insect or animate dead) have 50% more HP and the duration is doubled. At 14th level this increases to double the health and two and a half times longer duration

Call familiar

At 6th level you can instantly teleport a familiar to fight for you. You can spend 1 hour with a willing creature to perform a ritual, at the end of which you put a special mark on the creature (you can remove a mark instantly at any time). If a creature is marked in this way you can, as an action, instantly teleport that create from any distance to any unoccupied spot within 20 feet of you (so long as you are both on the same plane of existance). However they will have half there normal HP. If they drop to 0 HP, or two hours go by since you used this feature, the creature returns to its original position (or the closest unoccupied space) at the same amount of HP as when they were first summoned. You can have a number of creatures marked at once equal to your wizard level but you can only use this feature to summon a creature once per long rest.

Signature summons

At 10th level you can choose two creatures of CR 5 or lower. Once per day you can, as an action, create one of the two creatures in an unocupied space within 15 feet of you, the creature has its own initiative but is controled by you with no free will of its own. The creature disappears after 2 hours or when it dies. You can gain more uses of this feature by expending 6th level spell slots. whenever you level up as a wizard you can choose to change one of your creatures. You can choose to add one more creature to the list at levels 12, 14 and 16 and you can add two new creatures at level 18 and 20.

Superior summons

At 14th level your summoned creatures are more powerful. Whenever you summon a creature with a spell that creature gets to add your int modifier to all attack and damage roles. Furthermore if one or more of the creature's ability scores is less than your score in the same ability, you can change that ability score to yours in the same ability.