Umbreon Prime
1. How does this card stand on its own (analyze the HP, attacks, Abilities, etc. of the card)?
Stats
100 HP, x2 Fighting Weakness, -20 Psychic Resistance, and one Retreat make Umbreon Prime's ''body''.
100 HP on a stage 1 isn't really all that impressive anymore, seeing we have basics that have 130 HP, and lots of stage 1's have even better HP these days (even though they only clock in at 10 or 20 HP more). Take into consideration almost anything hits for 100+ damage these days (or can reach the 100 damage cap quite easily with a little help), and you'll realise you got yourself a pretty frail card here.
Umbreon's x2 Fighting Weakness isn't thát horrible; Donphan would make short work of it anyways, and what Fighting types are populair these days...? Maybe the odd tech, but apart from Donphan I don't think you'll have to worry about much.
The -20 Psychic Resistance is nice to have, but with only 100 HP to sport, this virtually gives Umbreon 120 to 140 HP when facing a Psychic opponent. While this might sound good, the most played Psychic types at the moment can OHKO Umbreon anyways (Gothitelle, MewPluff), or they will simply bypass the Resistance (Chandelure, the odd Gengar Prime). To me this makes the Resistance a rather niche thing to have.
One Retreat is ''good enough'', as it has always been. It's not too hefty a price to pay, but free Retreat would always be better.
Power/Body/Abillity
Umbreon Prime also comes with the Poké-Power Cloud-Covered Moon, which is essential a Super Scoop Up built into Umbreon. The catch is you can only use it if Umbreon is your Active pokémon, and it can't be used if Umbreon is affected by a Special Condition.
While a coin flip for a full recovery is actually a good thing, to me it seems it's a misplacement on Umbreon. First of all, it misses the synergy with Umbreon's HP. If Umbreon was able to soak up some damage, the power could come in quite handy. But seeing Umbreon will most likely OHKO'd, you'll never get the chance to try and recover it. Second of all, I think the power shouldn't have been nerfed down by restricting it to the active spot ánd a coin flip. If Umbreon was capable of scooping itself from the bench, it's uses would become a lot wider as well. If Umbreon wasn't restricted to a coin flip, I'm sure the card would be a lot more attractive as well.
Attacks
Umbreon boasts a single attack; Evoblast. For {D}{C}{C} you get 50 damage. It is then boosted by 10 damage for every pokémon you have in play that evolves from Eevee (meaning you'll automatically hit for 60 due to simply having Umbreon on the field).
Evoblast is essentially a ''3 for 60'' gimmick attack, with the option of boosting it up to 90 damage for field presence, and a maximum of 130 damage when factoring in 4 Sp. Darkness Energy. Sounds good on paper, doesn't it? Well, in practice it's horrible. Unless you get T2 Umbreon and 3 other ''Eeveelutions'' in play, along with a Sp Darkness Energy and a DCE on Umbreon, your deck will be a slow low damage deck which takes too long to build up.
Of course, that is if Umbreon is your main attacker. Which it shouldn't be at all! Umbreon should be considered a tech for the Eeveelutions deck, where it can recycle itself, as well as hitting hard when needed. As with all Eeveelutions, you should use Umbreon if you can hit for Weakness, and if Umbreon's damage cap is high enough to warrant play in the current match.
2. What role does/could this card have in the metagame?
At the moment, it doesn't have a ''role'' at all except for binder fodder I guess. It can be used as a tech in the Eeveelutions deck, but to me the ''normal'' version from Undaunted boasts even more useful aspects. Of course it's a nice card for the ''Eevee Fanboys/Fangirls'' as well...!
3. What cards, if any, does this card combo with?
Well, it obviously combo's with the other Eeveelutions. Since it's attack is also ''deck-specific'', I think it has little to no uses at all outside of it's own deck.
4. Give it a rating (out of 10), and explain why you have given it that rating.
''Normal'' Modified Deck: 2/10 (possible built in scoop option could prove useful in some situations, but I think it's still not worth it.)
Dedicated ''Eeveelutions'' Deck: 4/10 (more use from the attack here, as well as being part of the ''theme''. The ''normal'' version has a lot to offer to the deck as well, meaning it gets some competition going on here on which one to choose. But then again, who still plays Eeveelutions anymore with the current cards...? We'll see what the future brings for Umbreon Prime.)