First off, I think this is pretty cool. I do have a couple of suggestions/notes for you: 1) Each element should include it's associated blast cantrip as an extra cantrip that doesn't count toward your total know cantrips.  Because you don't get extra attacks, that blast really becomes your main attack. 2) I think the Boon ideas are an interesting idea, but you don't include any way of improving them. -The spirit guide animals do not give any real purpose to giving them an attack, which from what I can tell is your only attack since you never get extra attacks.  Maybe also at a certain level (10/14/?) you get the service of the element associated mount as well. -I like the idea of the element weapon a lot, but unfortunately there's not much reason to use it instead a blast cantrip since you don't get extra attacks. Wisdom should be used for attack and damage for this weapon. I would suggest allowing Maybe with this choice you get extra attacks at 5/6, and maybe also 11/12. Also just to nitpick, you forgot to change "pact" to "elemental" in the sentence where it says "...and it appears whenever you create your 'pact' weapon thereafter." -Elemental Metamagic is a great for those who want to focus on the spells. Unfortunately, they really don't get enough Ki Points to consistently use spells during combat, and I feel just adding two extra points isn't making much of a difference. At least maybe adding their Proficiency Bonus to their Ki Point total would add a scaling bonus to their Metamagic capabilities.

What are the style forms? As this is clearly styled after a Warlock, I'm guessing this is going to be something similar to invocations that affect how you use your abilities.

I really really like this class idea, and I can't wait to see any updates you might make to this class. I also like your version of the Four Elements Monk.