Well, if you're going to use Shazzar as lead, then you might be better off going for speed nuke team with a TM booster. You have a seeker who is a really good option, as well as putting up i c atk. Although shazzar does this on himself with extra turn. Without seeing the rest of your roster, the only other option I can find is High Khatun. 

Following this I would use your best AoE dec def/ and or weaken champ followed by your Shazzar then another ATK based AoE champion. You know their builds, so you should be able to decide who to use.

Shazzyy places 2 bomb debuffs on all enemies.. you will need ACC to ensure these land, while the bomb damage scales from the Champion's ATK stat. Build him fast with acc and as much atk as possible. Crit rate is also important if you want his A3 to place the bombs with only a 1 turn cooldown. 

What is your current def arena team? Skullcrown is one of the hardest hitting champs, I would continue to use her in any build. You have a Riho, probably the best support champ in the game, I would def be using her if I had one. 

shazar's damage comes mostly from his bomb debuffs so you don't really need crit damage, but crit rate is still important to trigger the decrease countdown from his a3. otherwise, make sure his speed is high enough to keep your team from getting cut in on and just stack attack and accuracy.

compwise, i think your best bet would be something like shazar, seeker, seer, and visix. seeker is there for his tm boost, so he should be the fastest champion on your team. you could also use high khatun, but she really doesn't bring anything else to the table, whereas seeker is a secondary source of cc and his passive has a slim chance of saving your team if they lose the speed race. seer should come next in the turn order. she's mostly there for her aoe weaken (bombs ignore defense, so def down is much less useful here than in standard muke teams), so you could also use guurda if seer is built for areas other than arena. if you do end up going with seer, you can build shazar to only 70% crit rate and put more focus into attack and accuracy, relying on her buff to make up the difference. shazar and visix can both go third or fourth without effecting anything all that much. shazar obviously is there to provide damage, while visix offers aoe crowd control which will help a lot in the event that your opponent doesnt get wiped in the first turn (or in case your opponent has a cleanser on their team).

full disclosure, i don't have a shazar so the above is mostly just theorycraft. that said, i think it should work pretty well.

edit: the above is how i would go about bulding a shazar team, but my honest advice would be don't. the only real advantage shazar brings is his aura and while great, i don't think it's enough to offset the weaknesses from running a bomb comp. it would be one thing if you didn't have a lot of other options, but you have plenty of viable alternatives.

Thanks for the advice guys, very much appreciated.