You really should make it's own ritual spell, and then make it so it can banish itself for maybe a dice effect, or banish other monsters with levels = 8 so you can Special Summon another one from your deck, kind of giving you more of a card advantage, something ritual cards completely suck at.
As for the card itself, I'd say it's really pretty good. You did the Heavy Storm effect correctly, seeing as it can only be used when it's ritual summoned. Overall a pretty good Ritual card, seeing as they're kind of a dying breed.
Change the word attacks in the second sentence to destroys. Either that or change the part after the semicolon to Negate the effect of the card that the monster equipped to this card battled. Honestly, it's better if you go with the first one. Other than that, good job in making more support for WATER. They honestly needed to stop giving LIGHT and DARK all of the cool toys.