Beast trainer

Have you ever felt like you need magic? but also, that you want to have a friend with this? well now you can, the closest animal to you, has offered to give you power, as long as you take it on journeys with you, to help you fight and train it

expanded spell list

when you take this subclass, you gain access to choose the spells :
1st cure wounds, healing word,
3rd Hold person, scorching ray
5th Mass healing word, animate dead
7th death ward, polymorph
9th mass cure wounds, animate objects

Beast guardian

At first level, when you start, you gain access to summon a spirit of your choice from this list, for 24 hours, in a ritual that takes one action to do, if the creature is destroyed, you may summon it back, equal to as many times as your charisma mods

spirit stat block : ice mephit,copper dragon wyrmling,darkling, heat draining vine

Commanding this to attack is a BA

Alternatively! you may also use a Pokeball to catch a creature of a cr of 3 or lower, and may hold as many as your proficency mod

Additionally
your beast has taught you how to speak its tongue, you learn how to speak in the creatures native tongue from your list for the duration its summoned, and gain profiency in survival checks 

Expanded guardian

At this level, your guardian evolves, and its choice becomes permanent (ie can no longer switch it, your dedicated to one), and it improves to another creature from the list below

Ice mephit : Animated breathe (cold form)

copper wyrmling : Wyvern

Darkling : Annis hag

vine : shambling mound

The CR you can catch with your pokeball, goes up to 6

Magical strikes

At tenth level, your creatures attacks are valued as magical for overcoming resistance and immunity

your invocations may be applied to your monsters

Final Beast form

At this level, your creature goes through its final transformation

Animated breathe (cold form) : Frost salamander

Wyvern : Young copper dragon

annis hag : Grey slaad

Shambling mound : treant

the CR of creatures you can catch goes up to 9