You may train/specialize special abilities from your Focus, but each is separate.
Quoting from Page 25 of my core rules, the boxed section on Skills, emphasis added:
If you gain a special ability through your type, your focus, or some
other aspect of your character, you can choose it in place of a skill
and become trained or specialized in that ability. For example, if you
have a mind blast, when it’s time to choose a skill to be trained in,
you can select your mind blast as your skill. That would reduce the
difficulty every time you used it. Each ability you have counts as a
separate skill for this purpose. You can’t select “all mind powers” or
“all esoteries” as one skill and become trained or specialized in such
a broad category.
So, 16 points to specialize in each using Rules as Written. However, you won't be specialized in Gravity Cleave until some time after reaching Tier 4, and you will only reach Trained in Weight of the World some time after reaching Tier 6. It's a pretty long road.
That said, you will have many tools to help you reduce your difficulty by this time which will offset the lack of specialization. By Tier 3 you should have 4 Edge. If it's all in Intellect, you use the Gravity Cleave for free with a point to spare to apply toward Effort. By Tier 6 you should have an Edge of 7, which could let you use Gravity Cleave and two levels of Effort for a single point from your Intellect pool.
Such tightly focused training might be useful, but may not be necessary to make you a formidable character.