Regras como Escritas - Fique com o MM
Familiares, Regras como Escritas, não avancem. O Pacto de Chain Familiar não melhora as estatísticas ao longo do tempo. O único texto que temos sobre eles é em Find Familiar e no recurso de classe Pact of Chain .
Pacto de Corrente
You learn the find familiar spell and can cast it as a ritual. The spell doesn't count against your number of spells known.
When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms: imp, pseudodragon, quasit, or sprite. Additionally, when you take the Attack action, you can forgo one of your own attacks
Encontre Familiar
You gain the service of a familiar, a spirit that takes an animal form you choose: bat, cat, crab, frog (toad), hawk. lizard, octopus, owl, poisonous snake, fish (quipper), rat, raven, sea horse, spider, or weasel. Appearing in an unoccupied space within range, the familiar has the statistics of the chosen form, though it is a celestial, fey or fiend (your choice) instead of a beast.
Your familiar acts independently of you, but it always obeys your commands. In combat, it rolls its own initiative and acts on its own turn. A familiar can’t attack, but it can take other actions as normal.
When the familiar drops to 0 hit points, it disappears, leaving behind no physical form. It reappears after you cast this spell again.
While your familiar is within 100 feet of you, you can communicate with it telepathically. Additionally, as an action, you can see through your familiar’s eyes and hear what it hears until the start of your next turn, gaining the benefits of any special senses that the familiar has. During this time, you are deaf and blind with regard to your own senses.
As an action, you can temporarily dismiss your familiar. It disappears into a pocket dimension where it awaits you summons. Alternatively, you can dismiss it forever. As an action while it is temporarily dismissed, you can cause it to reappear in any unoccupied space within 30 feet of you.
You can’t have more than one familiar at a time. If you cast this spell while you already have a familiar, you instead cause it to adopt a new form. Choose one of the forms from the above list. Your familiar transforms into the chosen creature.
Finally, when you cast a spell with a range of touch, your familiar can deliver the spell as if it had cast the spell. Your familiar must be within 100 feet of you, and it must use its reaction to deliver the spell when you cast it. If the spell requires an attack roll, you use your attack modifier for the roll.
Upgrade com Magic
Um sprite é poderoso em stealth, tem flechas envenenadas e ótimo para sabor em um feylock. Infelizmente, não é muito saudável. Você pode melhorar sua armadura (e armas), ou dar pontos de vida temporários por meios mágicos. O sprite familiar leva seu equipamento existente com ele quando enviado para a dimensão de bolso, então, em teoria, o equipamento atualizado deve funcionar também (há uma pergunta sobre isso, mas mesmo se o sprite não pudesse levá-los com eles, eles são leves e você pode carregá-lo). Itens mágicos significados para PCs (não é verdade para algumas das armas que os monstros carregam) redimensionados para o tamanho do usuário, então não há razão para não usar armas / armaduras mágicas.
Pergunte ao seu DM
Qualquer coisa além disso exigiria que você fizesse com que o seu Mestre concordasse com a regra da casa para a progressão.