So her main use is arena. She follows that same template as Morrigaine as an Arena heavy champ that combines what several other champs do in an option heavy kit. So basically several things to do with none of them quite as effective as the iconic champ each ability comes from.

Her A3 is a cleanser and TM boost, kind of similar to Siphi. This ability really shines in a go second team where several debuffs and even a bunch of bombs removed means lots of extra TM boost and you cut in and your whole team gets to go.

That Passive is quite good. Many matches I fight in G3 and G4 Tag have two+ teams with Kymar. Ignoring his sleep and cleansing the team is good. Ignoring Siphi's irresistible sleep so that Tramaria can still cleanse the team is just as good. It's frustrating to have Siphi sleep your Mithrala right before a cleanse and then your 3-0 goes to a 2-1, or your 2-1 to a 1-2.

Her A2 is very much Astralon inspired, but it definitely is going to be tough to both get high resistance and high accuracy.

I perhaps would build her in high accuracy Immunity, Untouchable or Stoneskin gear, and let her natural Immunity to sleeps shrug off the Kymar nonsense if he's on the other team. Otherwise, you run her slow enough to cleanse bombs and then stun when you either buff strip or the opposing Stoneskin wears off.

The other option is a super high resistance Immunity or Stoneskin cleanser and just try and have enough accuracy to stun nukers and speed leads.

Makes sense. Feels weird when you have good abilities, but you have to choose between them. If she had Mithrala's passive or had better immunity to control debuffs, she'd be great. 

I think I would probably use her the same way as Riho - namely, a way to ignore CC's without requiring high resist to do so. You basically want her to be fastest on the team, and ideally, faster than their nuker - because 99% of nuke teams nowadays run speed boost into AoE CC, to allow the debuffer and nuker to be much slower. And a very common person for that role is Kymar, given he does both CC and buff removal. She serves as a hard counter to Kymar teams, essentially.

Give her reaction sets to ignore critical hits, and make her tanky af, and have her be ~280 speed, and she should be able to cut in before their nuke, remove debuffs from your team, and just generally make them a pain to kill.

Interesting idea. Similar to what Mithrala is doing for my team right now, but with speed instead of shield in a more niche application. Mith is on the same team with Krisk, so that shield is kinda wasted when she cleanses.

Makes her not as effective against stunners and provokers, though, unless I pump her full of RES. I got some thinking to do, I guess.  

280 is significantly faster than I would run her in the current meta. 240-260 is the sweet spot right now to jump the increasingly slower and slower and slower nukers after she ignores Kymars CC.

My strip and CC champs go at about 240 and it's perfect for dealing with cleansers going 260+ while still jumping nukers. Let the fast Mithrala or whomever cleanse, strip and lockout, nuke for an easy win.

I suspect I will be slowing down my 240 as the meta continues to evolve.

Run her in Immunity and you also don't need to worry about stunners or provokers... She either ignores direct CC through the Immunity or the sleep part of the Kymar strip or Gauis bombs and either way cleanses your team. Although I am unsure stun or provoke an issue right now. No one is using either of those types of CC in my experience the last few weeks in G4 Tag or Plat. It's basically Kymar sleep city out there. Maybe a bit of Hege every now and then if someone wants to give you free wins.

I use Maulie and Krisk lol So I guess Tramaria is more of a later Arena champ, Kymar is not as prevalent where I'm at. 

Well, even where you're at in a good Immunity set she'll ignore Maulies and Krisks and cleanse your team from their CC. :)

I'll need to get me some Immunity pieces, I have very few good ones.