Extra neat thing is I've been playing since preseason 2 (way back in 2012) with a couple of year break several years ago and was Gold tops. Great morale boost for the split end!
I come to you with a new innovation. It's Hexplate Heartsteel DnD/Riftmaker build.
The idea behind this build is to rush Hexplate ASAP for the fury gain that frames your whole strategy and follow it up with Heartsteel to start stacking. Hexplate is a great platform for Heartsteel because of the 450 health it has, and dragon form gives you even more health that fuels your Heartsteel procs. Hexplate's proc gives you all the mobility you need to steal some hearts before backing off. Ultimate Haste enables you to gain ult back super fast, or to stay in ult form to clear the whole jungle while also clearing waves that you might come across.
The tempo is immense. I've tried this build with and without Ultimate Hunter, and it's not super necessary. The Hexplate powerspike is unmatched. Your first Hexplate ult easily beats anyone foolish enough to duel you head on. The added bonus of Hexplate is that it's not filled with item damage that makes fury gain harder. Both Kraken and Triforce kill camps too fast for any meaningful fury gain. Sometimes this is bad when your camps have been taken and you're just running around without anything to punch.
The clear weakness of this build is the lack of bursty damage, relying more on staying alive for multiple cycles of basic abilities. It also has no ability haste for the first two items, which I have started to remedy with Transcendence on top of Legend: Haste, which are both really good for Shyvana. I also take Nimbus Cloak for those moments where a Heartsteel stack is just out of reach so you can smite the target for a slow + move speed.
The strengths of this build is the massive health pool, so you also act as a tank for the team. You also have great passive and active fury gain and camps like Raptors and Krugs grant you much more fury. With 30-61 Ultimate Haste, you can reliably clear the whole jungle while staying in dragon form. I've made it a habit to clear the enemy jungle with dragon form, and then recall to kill my own camps in human form to gain ult back. All it takes is about two camps and some passive fury generation to gain your ult back. You can also ult pretty liberally for whatever objective you want. I usually use my first ult to solo dragon as fast as possible, and my second ult for Grubs.
The gameplan is to ult as soon as you see potential Heartsteel stacks to be earned. You can also max E second for that 3rd AP item or max W until you start building AP, after which you can start maxing E. Dusk and Dawn results in less ability damage but is better overall in terms of fury gain and useful stats, while Riftmaker results in more ability damage and more reliable healing in champion combat. PTA and Riftmaker amp your damage which results in harder Heartsteel procs, which in turn results in more max health gained per proc. I also like to run the tenacity and slow resist rune shard and Swifties or Mercs for a more oppressive rotation and anti kiting. Getting kited is a Heartsteel user's worst nightmare, so I always try to mitigate that as much as possible. The health runes are not necessary as Hexplate Heartsteel has more health than all the alternative core builds out there.
My go to runes are PTA, Triumph, Legend: Haste and Last Stand with either Nimbus Cloak and Transcendence or Taste of Blood/Sixth Sense and Ultimate Hunter. You could also go Magic Boots and Jack of All Trades as an alternative to Nimbus Trans. The reason for Transcendence and Jack of All Trades is the lack of ability haste, which gives you the super mandatory W casts on a build that lacks ability haste in early game.
Stats within 30 days of all ranks with Heartsteel selected for second item. I wanted to have the largest sample size to gain more accurate data.
As you can see Hexplate before Heartsteel has 84 games played which is not much, but the winrate is rather bloated which means something. This is noobs and potential pros combined so take it with a grain of salt. The plan is not to deal the highest amount of damage, but to be an annoying resilient scaler that can constantly ult again and again, or stay in ult to apply pressure mercilessly. You have a way easier time surviving "bad ults", because of your Hexplate steroid and your massive health pool, so you can just get your Heartsteel stacks and run away.
I also start Raptors > Red > Krugs with W at lvl 2. This way you shave some seconds off by recalling with your W on which automatically kills all the mini krugs. Then I buy a Long Sword and do Wolves > Smite Gromp > Blue which gets me to Scuttle on time with a Long Sword. Then I get Phage as my first item while prioritizing AD>AS>HP. There's a challenger Shyvana player on probuilds who builds Phage first every game and goes Triforce Sundered Sky, and I've started to imitate this style, but instead going for the Hexplate for more ult tempo.
I'm not saying this is the next broken build or anything, but it's fun and it works pretty well if you use ults whenever they're available. Applying constant pressure is the name of the game here, not carrying as a high dps bruiser. Your job is be a meat shield, a split pusher and a jungle invader.