I think you should go for Decade.

To be fair I did quite enjoy that episode I watched.

I say fuck quality and go for Hibiki since it's suppose to be vastly different then many of the other shows.

If Hibiki is an option then I will always advocate trying Hibiki.

Hibiki is a show I have wanted to watch forever but the poor video quality and knowing there are lots of things still out there with good rips to watch put me off. But about a year later, I've pretty much watched or at least tried every Rider series I've wanted to watch. So that basically leaves either Hibiki or Decade left now. I could attempt to get into Blade for like the tenbillionth time but meh.

Dude screw video quality. If you want to watch it just watch it.

DK 29. Holy clipshow Batman.

DK 30. Kamen Rider Siren, AKA Kamen Rider Wasted Potential number ten billion and one.

In early episodes Len's lack of place, gave him a distinct lack of purpose. He was fighting a war entirely alone, for a dimension that wasn't his own against a monster who had killed his entire world and most of its protectors before they could even defend themselves. To add insult to injury, he wasn't fighting mindless monsters, he was fighting "innocent" people who shared the faces of his closest friends, and family.

Part of what made his friendship with Kit so enjoyable, gay subtext jokes aside, is it showed this vulnerability to Len. He was damaged, he was hurting and he was lost, there was so much pain and sorrow just beneath the surface but Len had been forced to learn to compress it down, pick up his sword and fight.

In the scenes Kit laughs off as corny, you visibly see Len's shoulders loosen, realising just how tight they are in every other scene. He obviously longed so much for a friend, for someone to talk to, anyone, through his friendship with Kit and later Chris he finds his place again and Len shows himself to be a character that grows in really a big way, he - much like Kit - is a very enjoyable character to look back over the series to see how they grow and progress. Both characters go through a lot more than most toku characters.

But then, it all turns out that he WASN'T alone, one other Rider from Ventara survived and of all of those Riders, it was his girlfriend, the woman he is madly in love with. It makes sense for Len to never bring her up before this, it fits with his character, but Len finding out he isn't alone - that his love has survived - should have been a HUGE moment for his character, but the show never captures any sense of that. Instead Siren is just yet another utterly pointless character, who does nothing and swiftly dies. Somehow, she's worse than all the other wasted Riders, because yeah characters like Torque were wasted potential but she didn't have the potential to be important she WAS important, easily one of the most important characters in the show, so she deserved so much more than the whole pile of nothing that she got.

Also weird was that although Advent Beasts have always been a thing, it was never really a concept properly explored. It just seemed like a bit of visual flare to give the finishers more punch, so to suddenly have an episode focused on Strike taking control of Vented Rider's Beasts for more power was really weird. I mean it was awesome and all, but it just felt like I was suddenly in another show.

What you're describing is elements of the Genocider arc from Ryuki where Ouja finally has his 3 contract monsters combine into one scary yet useless monster. They explore the contract monster stuff a lot during the first half of Ryuki though.

Strike has been fun, but it's been clear that they've never really known what to do with him. Despite him being important to the shows universe, as soon as his identity was revealed (and even that wasn't handled well) he just sorta fell apart a bit showing a drastically broken personality where he'd go from ridiculously brutal to unnecessarily violent to ADHD levels of random to sympathetic and understanding, to cowardly and pathetic.

Like I say, minus Kit and Len the Riders in this show have either been wasted or utterly forgettable with no inbetween. I wish they had got to adapt a show like Blade, as although I think Blade's action was shit, having four Riders to focus on rather than 9000 would have benefited this show in so many ways.