Okay so we still have more questions then we do answers.
ZOOM: created by Wells2 when the particle accelerator blew up.
But who or what is ZOOM?
1. Evil embodiment of Speed Force energy? Maybe
2. Molecular split from Jay Garrick and thus is Jay's evil half?
3. Henry Allen of Earth 2 (not ruling this out until ZOOM is unmasked)
4. Hunter Zolomon: I am now leaning strongly in this direction.
Hunter Zolomon was described by Jay Garrick in the comics "as being 'derailed' from the timeline by the explosion â€“ thus allowing Zolomon to alter the speed at which he could move in time, giving him the effect of superspeed." it is also stated that his speech patters would ebb and flow, which would explain how he sounds on the series.
The above easily explains why ZOOM easily pounded Barry in their first fight. By manipulating TIME itself he would be faster then the FLASH.
So why does he want the speed of the Flash? He's power hungry, also perhaps addicted to power as his hand seemed to shake when he took the syringe of speed force from Wells2.
Now did he really drain speed force from "Jay" before he was warped to Earth 1? I doubt it. We've since learned from "Jay" that he really lost his powers and health due to Velocity 6.......which is the actual history of the Earth2 villain Edward Clariss aka the RIVAL.
Yet ZOOM cannot drain Barry's speed force.....is this due to Barry being from a different dimension or is it just that he can't siphon speed force energy and thus has NOT siphoned speed from Earth2 Flash.
Now we have the man in the iron mask in ZOOM's lair, and it is extremely likely that he is the actual Jay Garrick. So WHO has been the "Jay" on Earth 1?
I say he is Edward Clariss/THE RIVAL. He was using the Velocity formula on Earth to be his version of the Flash. ZOOM then captures the real Jay and locks the mask on his face and then pursues THE RIVAL. He attacks THE RIVAL as the portal opens and he does NOT draw Speed Force out of the RIVAL so much as Velocity 6 wears off. The RIVAL is then blasted to Earth 1.
At this point the RIVAL knows that ZOOM could come for him and so he spins the tale that he is Jay Garrick, the Flash of earth 2. He does offer to train Barry and teach him to harness the Lightning, yet he preaches against Velocity 6 and will not partake of the fights against ZOOM.
He then starts cozying up to Caitlyn and gives her the sad puppy eyes routine which works and she starts working on Velocity 6 to make it Velocity 9. Whether he really loves her is a coin toss.
Velocity 9 works, he is healing and has speed to rival Barry.
Then at the end of the latest episode we see ZOOM vibrate his arm through THE RIVAL's chest/heart and yanks him through the portal. Now generally a hand vibrating through the heart tends to be fatal, but IF ZOOM is Hunter Zolomon and he is infact warping time to simulating speed then THE RIVAL may still be alive and captive of ZOOM.
Also even though Velocity 9 appears to have worn off before he was taken, for all we know he has the formula, perhaps a secret vial of it, or perhaps there is enough left in his system to recreate the formula. ZOOM may also want the formula to turbo charge himself.
Is this "Jay" actually the RIVAL? I think so. The real Jay Garrick does NOT need Velocity serum, the last time I checked he gained his power from a freak lab accident much as Barry gained his from a "freak accident".
Also the RIVAL wears a darker toned copy of Jay's costume.....on the show his costume does appear to be darker shades of red and the lightning bolt is a stitch pattern and not a yellow bolt.
So what of the Man in the Iron Mask: quite likely he is the real Jay Garrick, Flash of Earth 2. Captured by ZOOM and imprisoned. The mask is for dramatic effect but also it likely is rigged to blow if he uses his powers or attempts to remove it. Or else it somehow blocks his power hence why he can't escape. I do not believe at this time that ZOOM has power siphoned him.
Now "Jay" reveals his Earth 1 counterpart is Hunter Zolomon and claims his DNA was not altered as his was ergo it can't cure him. Nice story, but I don't buy it. Is Earth1 Hunter really the counterpart of "Jay", again I don't think so. There is also the possibility is that THE RIVAL is indeed the "JAY" we have been seeing and that somehow the RIVAL stole Jay's face. Perhaps some DNA device like RF used on the real Wells in Season 1 which could also explain the iron mask, or perhaps simple plastic surgery. THE RIVAL wants to be the Flash so bad that he starts copying him in every way, including appearance and including having his face rebuilt.
Also it is possible that he is indeed THE RIVAL and is working with ZOOM, perhaps to get Barry's speed or to get the Velocity serum perfected.
Nevertheless I think the "JAY" we have been seeing so far is indeed Edward Clariss, THE RIVAL.