After stepping onto the lake, I perform the four hand seals while sending my chakra into the water source and resurrect a large beast canine looking thing made of the water. With this I can perform a multitude of attacks like spitting out water.
The way I see it, the Water Beast is a large creature of the wolf variety, though I'd imagine you'd be allowed to change it to different animals, or at least shape the wolf differently to suit whatever it is you currently need. I'm pretty sure this would be self-sustaining with chakra and so on, so you can personally use jutsu yourself still while the beast in in effect. The beast has the ability to use a B-Rank water stream which can be launched at targets which can be pretty handy, I'd use it to put out a burning fire or something but imo it's more effective to use it as something to push back techniques. It's second ability lies in being able to summon waves with clawing actions, simply like it were pushing water itself. I'm sure this would also be B-Rank but I'm not entirely sure on this matter, and could better be used as a more offensive action to keep the target at bay while you set something up like say, Four-Pillar Bind. One thing I've picked up stalking other training threads comes from the beast itself. It's body is made up of water itself so you could use the beast as a means to defend against a strong Fire jutsu of sorts, while keeping the majority of it intact, and can pretty much get two techniques off from the one source, counting it as one technique.
I mean say you use A-Rank Fireball at me with this Water Beast active, and then use something else like say, throw a few explosive kunai at me underneath the fireball. I could use the beast's waves in order to nullify your kunai while still continuing towards you, while simultaneously letting it tank the fireball itself, which would essentially stop two of your attempts at striking me with one technique, as well as giving you something to defend against.
