Niani, Blind Luminary4GU
Legendary Planeswalker – Niani (M) |+2|: Scry 2, then manifest the top card of your library.|-2|: Put target permanent on top of its owner's library.|-8|: You get an emblem with "At the beginning of each upkeep, reveal the top card of your library. If it's a nonland card, you may cast it without paying its mana cost. If it's a land card, you may put it onto the battlefield . [3]
Scying and Manifesting off of a plus might be too much. Its feel stronger than a number of other similarly costed walkers but not stronger than every similarly costed walker.
Putting it on top seems a bit weak, not by a significant margin just at the level of underwhelming.
The ultimate feels more red/green than blue/green. Its a reasonable fit but feels off a little. I was underwhelmed on the first reading but then saw that it was "each upkeep" not "your upkeep".
Given the cards you cite, I guess it's not over powered, but it seems strong. I certainly think its too strong for a common. Rampant Growth is a very good card, and a better card to use as an example of precedent because of its iconic status and its frequent reprints. Your card is an instant speed Rampant Growth that also cantrips for one more mana. I think Natural Connection was designed for Battle For Zendikar because Rampant Growth would have been too good.
Niani, Blind Luminary:
I feel a 6 mana planeswalker with a starting loyalty of 3 is odd. Generally a planeswalker should have a starting loyalty equal to its mana cost or within one number of it. The plus ability is good, maybe a little too good, it should probably only scry 1. The minus is underwhelming. You could change it to an Oust/Chronostutter effect or you could make it cost less to activate. The ultimate is an interesting ability but a little weak because it's a -8 ability on a 6 drop planeswalker, and by that point in the game, you should have enough mana to cast whatever you were going to draw anyway. Yeah, it's an extra card, but a little underwhelming for a 6 mana planeswalker (but more acceptable on one with a lower mana cost.
Natural Insight would be strong in standard, and it would really depend on the environment as to whether it would be too strong. It's probably okay (and definitely okay in other formats).
Niani looks fine, though as-mentioned she should probably start with 5 loyalty and maybe increase her second ability to -3. I don't think her +2 is too strong, because she costs 6 mana, but it also wouldn't hurt her drastically to tone it down to scry 1. Looking at Elspeth, Sun's Champion though, she looks decidedly weaker. Her +2 is arguably better than Elspeth's +2, but her second ability is dramatically worse. The ultimates are about the same.
It also occurs to me that she can never normally manifest a card she bounces because loyalty abilities are sorcery-speed; not sure if that's something you intended her to be able to do? There wouldn't be a whole lot of point to it anyways.
I also like that if you manifest a big sorcery and then later get her emblem, you can bounce that sorcery to the top of your library and then play it that way. It's neat and it really helps to give her a cohesive feel, even if it's probably impractical in most games.
Instant
Search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library.
Draw a card.
Shefet Monitor
Natural Connection
Legendary Planeswalker – Niani (M)
|+2|: Scry 2, then manifest the top card of your library.
|-2|: Put target permanent on top of its owner's library.
|-8|: You get an emblem with "At the beginning of each upkeep, reveal the top card of your library. If it's a nonland card, you may cast it without paying its mana cost. If it's a land card, you may put it onto the battlefield .
[3]
Putting it on top seems a bit weak, not by a significant margin just at the level of underwhelming.
The ultimate feels more red/green than blue/green. Its a reasonable fit but feels off a little. I was underwhelmed on the first reading but then saw that it was "each upkeep" not "your upkeep".
Given the cards you cite, I guess it's not over powered, but it seems strong. I certainly think its too strong for a common. Rampant Growth is a very good card, and a better card to use as an example of precedent because of its iconic status and its frequent reprints. Your card is an instant speed Rampant Growth that also cantrips for one more mana. I think Natural Connection was designed for Battle For Zendikar because Rampant Growth would have been too good.
Niani, Blind Luminary:
I feel a 6 mana planeswalker with a starting loyalty of 3 is odd. Generally a planeswalker should have a starting loyalty equal to its mana cost or within one number of it. The plus ability is good, maybe a little too good, it should probably only scry 1. The minus is underwhelming. You could change it to an Oust/Chronostutter effect or you could make it cost less to activate. The ultimate is an interesting ability but a little weak because it's a -8 ability on a 6 drop planeswalker, and by that point in the game, you should have enough mana to cast whatever you were going to draw anyway. Yeah, it's an extra card, but a little underwhelming for a 6 mana planeswalker (but more acceptable on one with a lower mana cost.
UBRKess, Dissident MageUBR - Controlling Dissidents
GRhonas the IndomitableG - Indomitable Four Drops
WUBOloro, Ageless AsceticWUB - Loot & Renanimate
Niani looks fine, though as-mentioned she should probably start with 5 loyalty and maybe increase her second ability to -3. I don't think her +2 is too strong, because she costs 6 mana, but it also wouldn't hurt her drastically to tone it down to scry 1. Looking at Elspeth, Sun's Champion though, she looks decidedly weaker. Her +2 is arguably better than Elspeth's +2, but her second ability is dramatically worse. The ultimates are about the same.
It also occurs to me that she can never normally manifest a card she bounces because loyalty abilities are sorcery-speed; not sure if that's something you intended her to be able to do? There wouldn't be a whole lot of point to it anyways.
I also like that if you manifest a big sorcery and then later get her emblem, you can bounce that sorcery to the top of your library and then play it that way. It's neat and it really helps to give her a cohesive feel, even if it's probably impractical in most games.
- Rabid Wombat