Is he a viable champ for dominion? Can anyone suggest a build?

Thanks!

Yes, he's excellent on Dom.

Start Prospector's and Boots 1. Build Brutalizer and Phage to follow up. That's a pretty typical Dominion bruiser start. From there, it depends on what role you're filling on the team, who your opponents are, and what they're building. Last Whisper, Frozen Mallet, Atma's Impaler, Hexdrinker/Maw, finishing Ghostblade - there's lots of options.

He's just super versatile. He can tank, he can deeps, he can bot lane, he can initiate, he can peel, he can even poke. Jack of all trades, and actually pretty good at most of them.

Well, I guess he doesn't do magic damage, so I guess he's missing that.

I've been playing a lot of Jarvan IV (a new hope) recently and he rarely seems to disappoint.

There doesn't appear to be any special builds for J4. Just take the generic tanky dps runes/masteries/items, making sure to grab armor or mr when appropriate.

The only tip I really want to emphasize is make sure you practice your flag and drag combination. If you miss it makes J4 look like a total dork out there. The flag has a slightly longer casting range (830) than the spear (770) so if you cast both at max distance from the same spot sometimes your spear will miss by that much.

Oh, one last thing... DEMACIA!!

I like Brutalizer, Trinity, Atma's.

I know it probably sounds crazy, but I find myself starting with Warden's Mail on him these days, especially when there are 3+ AD champs on the other side. It makes him the most durable guy on the battlefield for a while and the procs can ruin a carry's day in the windmill fight. It takes a bit longer until you can do real damage, but you can still apply your passive and be a disruptive force with your slow and knockup until then. It's just a question of sticking with your teammates, which you should do anyway.

he's fantastic, imo.

i build trinity force and youmuu's ghostblade most games. wit's end usually follows.

He's pretty dang good, and the passive mana-regen from Dominion really helps alleviate his super high mana costs.

I agree with Basoosh - Boots + Prosp Blade, Brut, Phage. That tends to be the best core. If you have a lot of AD on your team, you may want to build a Last Whisper (unless the enemies are completely incompetent).

Ive used him mostly as a Tank. With Frozen Mallet and his knockup (plus flag buff) he is pretty good at absorbing punishment, peeling enemies off of squishier allies, and being a general pain.

A good jarv can really make a huge difference with a semi-intelligent team. Playing him as Deeps is alright but hes just another bruiser. Playing as a tank I feel makes a lot more impact....BUT if your team are tardz then you will fail hard. So that is the risk.
Tard team is defined as players that attack BEFORE you get there, run in 1v3, follow you, then go a DIFFERENT way or stand there as you engage, etc.
Basically failing to follow and support the tank.

J4 is my favorite Dominion champ, and I build him very, very similar to the above - though I almost always end up taking Triforce / Ghostblade over Mallet / Atma's. I used to build atmogs (every game!) before they took away the 'mog, but atma's / tanky is still more than viable if you want to end up that direction, depending on the situation

I need to build Last Whisper more often.

He's got crazy good maneuverability too, and his E+Q goes over (I believe) any wall on the map, if you need a quick getaway. I love the poke and the disruption he provides to a fight while still being able to take a lot of pain.