I've been wondering something about Renji's zanpakuto guard.
There are various elements engraved on it. At the top and botton of it there is what looks like fangs, and more specifically they look snake fangs, which makes sense because his zanpakuto spirit is part snake. But then, the rest of the pattern is what looks like a lightning bolt on each side, which is a little strange because we would expect for something baboon related, to show the baboon part on the guard the same as the snake part. Unless that what look like lightning bolts are supposed to represent the baboon part. They are on Renji's neck (a shorter lightning bolt, with one less stroke than the ones on the guard), and the snake fang is there too:
So, maybe they aren't lightning bolts but simply tribal tattoos with that form, and that is what represents the baboon part of Zabimaru, his tribal tattoos.
But, if they are really lightning bolts, it can make sense, because Renji's power is related to fire things. He has used Zabimaru bankai as a canon to fire energy to the opponent, and has burned opponents. But Renji's zanpakuto guard has a big representation of the lighting/tattoo part, so I wonder if he, in the future, would develop more the use of lightning powers when using his zanpakuto, if they are really that, lightning bolts.
When Ichika appeared in the manga for the first time, she showed her zanpakuto:
And we saw that her zanpakuto guard had the form of a lightning bolt, and people immediately thought she could have lightning powers, but, at the same time, they also thought that Ichika's zanpakuto guard has the form of Renji's tattoos on his neck, which are basically the same as the ones on his zanpakuto guard, but people usually don't think that Renji has lightning powers. I suppose it's because Renji has powers that are hard to classify. His bankai extends and is strong, so he uses force to fight, but it can also emit bursts of energy (and the things we saw in his filler fight with Ishida, but I'm not sure to consider what his bankai did there canon). What his bankai emits is a lightning bolt? If Ichika's zanpakuto is going to have lightning power, then Renji should have the same power, because she inherited her zanpakuto guard shape from him.
In Ichika's case, the guard is just a lightning bolt, so her powers would be centered around that, so they would probably be much more intense than Renji's lightning powers, I suppose. And, if it's not a lightning bolt, then maybe her power is going to be something tribal and related to a baboon, or other animal.
