Warning: Slight Spoilers but not anything a quick search about Gloxinia won't tell you.
Basquias Initial Ability: Able to manipulate its size freely.
No Ring - Form Zero: Blanket. This will allow Gloxinia to summon his martial soul which will look like a green blanket with leopard-like spots around it.
First Ring - Form One: Sacred Spear. This will allow Gloxinia to turn his martial soul into a spear reminiscent of a mage's staff but with a sharp tip. It will also be able to levitate.
Second Ring - Form Two: Guardian. This will allow Gloxinia to turn his martial soul into a huge bee that can both attack and defend.
Third Ring - Form Three: Increase. This will allow Gloxinia to summon multiple small golden daggers that can swarm the enemy.
Fourth Ring - Form Four: Necrosis. This will give Gloxinia the option to add a Necrosis Poison effect to his attacks that will paralyze the enemy for a duration based on strength.
Fifth Ring - Form Five: Yggdra Armor. This will allow Gloxinia to have Basquias wrapped around him to become an armor with horns and sharp claws.
Sixth Ring - Form Six: Luminosity. This will summon a greenish barrier around Gloxinia that both protects gloxinia and his allies while still being able to shoot ranged attacks from inside. There is also a slight recovery effect inside the barrier.
Seventh Ring - Form Seven: Emerald Octo. This will allow Gloxinia to summon Basquias' true body which are summoned as Thick and Long vines that can attack and defend. They can also be manipulated to create new creations, such as a copy of an enemy with semi-consciousness.
Eigth Ring - Form Eight: Moon Rose. This will allow Gloxinia to summon a huge tulip which can heal even the most grievous of injuries.
Ninth Ring - Form Nine: Death Thorn. This will allow Gloxinia to summon a lot of long vines with thorns on them, even the slightest scratch from one will result in death.
EDIT: As for the nature manipulation Gloxinia has in 7ds, it will be in the story but gained through a mission and also a bit nerfed since it would be far too op in sl3. It will be able to gradually stengthen and reach the originals power though so no worries.
EDIT 2: For his Fairy King Wings soul rings, they are actually more of a Bloodline-Martial Soul so they will show up in the form of Bloodline Spirit Rings, not from Spirit Souls. More will be explained later in the fan-fic.