Most theatrical vocalists in metal

[The Heretic]

Big Boss from Root comes to mind. The opposite of the falsetto style. A huge voice.

Not a metal vocalist but Carl McCoy from Fields of The Nephilim did venture into a more metal style with the side project Nefilim album. The semi harsh goth vocals worked a treat. Pity that was a one off.

Great call on Carl McCoy...probably one of my favourite vocalists  of all time...

[Anton Arcane]

I'm having a few cans and listening to Virgin Steele. Does David DeFeis fit the criteria?

[Petardo]

Not a metal vocalist but Carl McCoy from Fields of The Nephilim did venture into a more metal style with the side project Nefilim album. The semi harsh goth vocals worked a treat. Pity that was a one off.

Wow, must check that out. I had Elizium on last night while panning out post-smoke and I think it partly inspired this thread! 

It's likely out of print and only partially on YouTube, but you'd pick it up on eBay pretty easily.

Such a shame he didn't do more of this. Lots of Ministry in there.

It's on spotify if that's an option.

https://open.spotify.com/album/2rrSuFGULsxX9YmU9OFdf5?si=6h0GW5bZRu-A2WrNdPpCow&dl_branch=1

[Abandon All Hope]

IX from Urfaust

[leatherface]

Midnight from the band Crimson Glory.

[Black Shepherd Carnage]

It's likely out of print and only partially on YouTube, but you'd pick it up on eBay pretty easily.

Such a shame he didn't do more of this. Lots of Ministry in there.

It's on spotify if that's an option.

https://open.spotify.com/album/2rrSuFGULsxX9YmU9OFdf5?si=6h0GW5bZRu-A2WrNdPpCow&dl_branch=1

Man, this is class. This was definitely worth starting the thread to discover!! 

Nice one!

[O Drighes]

What about Fenriz on Isengard. Theatrical or just retarded? Maybe the perfect middle point!

That's being drunk only  . He stated in interviews that he tried doing vocals after having 6 cans and they sounded shite, so the next day he tried 12 and the rest is history.

Ronnie James Dio hasn't been mentioned yet. I guess Tobias   Forge from Ghost has to be the most theatrical alongside King Diamond and Alice Cooper, their career depend on it. Good shout on Dave DeFeis though...

[Ealaín]

Jon Oliva

[Ealaín]

I'll add Ragne Wahlquist of Heavy Load too!   

[Nazgûl]

This one doesn't quite fit the bill of the OP I don't think, although it's certainly theatrical but not on the cheesy side. I didn't know where else to put it in the board, but I've just watched this on YouTube:

https://www.youtube.com/watch?v=MSnUjihnPQw

I've never heard him sing this any better in a live setting (or on record actually). A truly powerful vocal performance that only gets better and animated as the tune goes on. No Grave Deep Enough from the same show is also up there and it's a belter as well.

[Black Shepherd Carnage]

Can't remember if it was in real life or on MI or both, but I definitely recall discussing this very topic with Nemty years ago and him saying it (a theatric element) was something that was missing, or something that newer metal could do with more of anyway. I think it was when with respect to one of his side projects though, Dread Sovereign, or the history lesson band, can't remember the name.

[Hambeast]

The guy from Arkha Sva and Avsolutized can get pretty crazy at times going from a black metal scream to full blown falsetto with the occasional bit of opera

https://www.youtube.com/watch?v=6vtVSjAX3JI

https://www.youtube.com/watch?v=wl39cdL49xY


I always thought Fairyland was as over-the-top as you can get too when it comes power metal

https://youtu.be/_irSTG6Yowc?t=456

[Thorn]

I'll add Ragne Wahlquist of Heavy Load too!

Good call that, I was spinning Death or Glory today actually.
I suppose for me when I think of OTT  frontman I instantly think of Blackie in his heyday. However when I saw him in Dublin after his conversion he was as dull as ditchwater, aloof even, standing with his back to the crowd , zero between song banter, totally had my bubble burst.

[Mr Barlow]

Technicality certainly wouldn't be the boul Lee's strong point, but I really love his vocals on Forest... so croaky,  unusual and perfectly imperfect!

Forest is friggin' class. I remember buying it back in the day and going woah....what the he'll is this ? At that time I was losing my shit to Carcass, Morbid Angel and Pestilence etc. So it was a real bolt out of the blue for me. Loved his vocals on it. Lost interest later as he got progressively more "groovy ".

[Pentagrimes]

Forest is a masterpiece.

Listening to a compilation of your man Proscriptor's live banter here, in absolute stitches.