Ok am I just wrongly obsessed with those two monsters? I have this sudden ure to build a water control deck with Umiiruka. Why do I have this burning desire? Is it because its a good combo or is it because of the drugs im on? And why is HalfDemon stalking me??

*faints*

Cause I am EVERYWHERE!!!!!!!!!! *scary music plays* << >> XD

Anyways....

Good stuff to use...

Umiiruka or A Legendary Ocean
Mirror Wall
Rising Energy
Mask of Weakness
Rush Recklessly
Curse of Anubis (before summoning of course)
Micro Ray
Enemy Controller
Return from the Different Dimension
Gravity Bind (if you use ALO)
Robbin Goblin (while making them skip their draw phase with Fenrir)
Robbin Zombie (make them lose their deck too XD)
etc

It's an interesting idea, but wouldn't it be difficult to get so many monsters that you wouldn't mind having removed in the discard right off the bat? Although, I have to admit that if you could pull off getting both on the field a Return from the Different Dimension could help offset having those monsters removed...

Perhaps instead of using Fenrir and Aqua Spirit, you could try using Fenrir and B.E.S. Crystal Core. True, the Core can't shift opponents' monsters into attack mode but it might be easier to get on the field (especially with A Legendary Ocean, which allows you to summon it for free). It can't be destroyed in battle, either, and its ATK is higher than Aqua Spirit's. If its counters run out you could just bounce it back into your hand and play it again.

Check out my Fenrir's FunTime deck, it's quite old and it needs some updating, but you wouldn't believe how well this deck ran back then... the Fenrir + Ojama Trio is marvelous.

** thinks about putting this deck back into action **

I dont wanna run ALO. Im not planning on running Big Extraterrestrial S***. No .. I want it to be budget water control that can actually be competitive.

ALO is garbage. Never liked it, never will. Its mainly useful for aggro decks.

Which mainstream monster will stand up to Aqua Spirit + Fenrir + Umiiruka??

In short ... your opponent has just lost their drawphase if they summon. And if they dont, thats a painful 4000 to the face. I dont plan on running any bigger or pointless monsters like BES. It does absolutely nothing for the theme.

Mirror Wall! I cant believe I forgot that old classic! I was in love with it and abused it in my Chick the Yellow bounce deck. Good times ...

Yep thats an essential (or a very good pick) for the deck. Rising Energy isnt a good pick on the other hand. If you cut off someone's drawphase once or twice ... chances are all their hand resources are already depleted. Rising would net me a skimpy 200 attack boost maximum.

RfDD was on the back of my mind, but Im trying to figure out if I have space for it. WOuld be nice to drop Fenrir+Aqua Spirit then SS a few StarBoys. Pwnd! ^_^

R-Goblin? Not too essential for this deck, but if I happen to make space its a worthy pick.

Im thinking if its possible though to build an Aqua Control without using ALO ...

From what I've read both here and at other forums, it's entirely possible - just a little bit more difficult. Without ALO's level-lowering effect it'll be a bit harder to get out certain tributes and you wouldn't be able to use Gravity Bind or Level Limit Area-B. And thanks to Umiiruka's defense-lowering effect if your opponent managed to take control of one of your Aqua Spirits then it could spell disaster for your monsters. Personally, I'd rather just stick with A Legendary Ocean and add in a few other cards to boost my monsters' ATK like Nightmare Penguin, who also comes with a helpful bounce effect.

It's true that not a whole lot could stand up to an effective Aqua Spirit/Fenrir combination with an Umiiruka out (and of course a few other position-changing cards like Book of Moon and Book of Taiyo couldn't hurt). But the problem of getting them out still remains. How would you get enough monsters in the graveyard to be able to get them quickly?

It's actually not that hard getting the stuff into the graveyard...especially considering all the Sakuretsu Armor's, Trap Hole's, Torrential Tribute, Lightning Vortex, Dark Hole, etc all over the place.

Chain Destruction can feed that. Double purpose for a control Water deck .. ;)