I will support this card because it's a new take on weapons abilities, and is PC control for gravity.
Anyway, i think it's a little overpowered, so maybe you should lower the power of the weapon below the average of other weapons. Lobotomizer costs 3

and deal 5|5 damage. Discord costs 3

and deals 4|6 damage. Fahrenheit cost 3

and deals 4|5 damage (i'm not counting ability for Lobo and Discord, so i will not count it for Fahrenheit). Trident|Poseidon costs 3

and deals 4|4 damages.
I also think that usually Gravity is more expensive than other elements, but also more powerful.
Considering all these details, i think this card should cost 1

more (both unupped and upped) and deal 4|6 damage.
I know that maybe the attack is not high, but this balance for the powerful ability that makes the weapon grow, free your weapon slot and destroy your opponent weapon.
Also, i think that this ability needs a name, so people may say "i <insert word here> the opponent weapon and got a flying 12|51"