Suggestions

A move in which the player places their hands in the priming position and then crosses their arms as if they were about to go down a water slide. This move will then cause the player to do a slight jump then "burrow" into the ground and move forward slightly, almost as if they preformed a dash but with slightly more protection. However, when the player is in the ground, the player's head would still be slightly poking out of the ground, allowing for the opponent to use a grounded object such as the grounded disk to counter this move. I believe that this would be most appropriate if the player unlocked this move after ranking up to mountain as mountain is seen as the "Master Earth Bender" rank. On another hand, this move could potentially be used as a shift stone where instead of the player doing a normal dash, the player would do this "burrow" move. Thank you for taking your time to read this and I hope to see this implemented into rumble.

Like the title says. This would be useful for if someone is surrounded by structures and you want to have them fall in towards the opponent instead of out away from them! I could imagine a lot of fun strategies for having a move like this!

A really cool addition to the game, that I think fits well with the current suite of moves and poses available would be an alternate base pose that summons the same structures, but in an alternate orientation. For example, it could summon a wall rotated ninety degrees so that its thin side is facing the player, a pillar laying on its side, a grounded ball, a sideways disc, and maybe have the cube summon ungrounded, with a small amount of upwards momentum, similar to the ball summon. Obviously something like the grounded ball or the ungrounded cube might need to be reworked slightly, but I think that it wouldn't be a radical change that would disrupt the current balance of the game, and would add enough diversity that could provide very interesting opportunities for a lot of creative combos. I'm not sure exactly what the alternate base pose could be, my first thought was hands horizontally aligned, with one palm face up and the other face down, sort of like a sideways flick.

basically if the structure is considered yours(aka you were the last person to modify it) and it hits your shield while in the guard pose, you will take no(or like -5 damage if that is too much). you still take -1 damage from your opponent's structure tho. this will buff the stone, without breaking current tech nor making it a different stone. this will also allow for more tech, as you won't have to worry about self damage anymore.

In Rumble we have Straight, Kick and Uppercut modifiers with a single cooldown timer for each. That means that if you do the modifier on any side (right or left), you will still have to wait for cooldown to end to make a new move. Counter example is how we have Right Hold and Left Hold modifiers, which are considered as separate modifier moves and thus don't share the same cooldown timer. Currently switching between them both is used in some chambering combos for more speed. I have two interesting suggestions to choose from: Make Right Straight, Left Straight, Right Kick, Left Kick, Right Uppercut and Left Uppercut modifiers with separeted cooldown timers, so that you can do the same modifier if you are fast enough to switch hand poses. Add the same effect as a new shiftstone you can equip to buff an ambidexterous playstyle with the same effect but for the cost of a shiftstone slot. Both implementations will allow for new combos, though the second seems safer in breaking the current balance of the game less (the Charge shiftstone will gain competition with double Straight users, but I also want to see the Charge + this one shiftstone combo). Softer version of this suggestion is decreasing the cooldown for the mirrored modifier instead of having them completely separated (for example, making it half, so that wait time between Right Straight and Left Straight will be 0,25s instead of 0,5s).

it would be cool for a ultimate move that could say only be activated once per round/match that take multiple different cast moments in quick succession

Sometimes you need to flick multiple structures really quickly in flight setups, and the long cooldown makes it impossible

Don't get me wrong I'm all for arm swinger sprint, but the motion it demands feels very strange and like an over exaggeration of what sprinting is really like. The motion should be more like swinging your upper arm and keeping the forearm locked instead of having to move both or just the forearm.

I think it might be kind of cool to have like a blue effect around the player while dashing or something to that effect to show that the player has the stubborn stone active

We need a way to quickly slam back into the ground to remove the predictability of Dash>Jump! This would also be great for if you got knocked into the air and quickly need to get back down and it could even have a sort of SHOCKWAVE when you hit the ground that would unground stuff or knock it back a bit!