eh idt the ability to remove quint should be in aether. also immortality removal would work better as a spell
It's a matter of precedent. The "rule" as it stands is that immortal creatures are not affected by spells but are affected by shields. Also, being able to neutralize quinted creatures is a potent ability, and making it a shield is probably easier to balance. Since you can only use one at a time shields are often a big deal that can absolutely make or break a deck, so it's easier to swallow a shield having such a powerful ability since you're giving up other very good shields to use this instead. Also shields have built-in counters: momentum creatures aren't affected, and you get an opportunity to explode/steal them before any of your creatures hit the shield.
Similarly, the element is aether because so far every lobo effect (other than random effects from entropy spells) costs aether to use. I don't think diversifying here would be a bad thing, so I could see switching it to something else (entropy maybe?) but aether is kind of the "default" for lobo effects.
Adding damage reduction would be a huge nerf since shield effects aren't triggered on attacks that fail to deal damage. One possible tweak I thought of would be to make it cheaper but only last 2-3 turns. That makes it a little more effective for its primary purpose but makes it harder to completely shut down ability-based creature decks with just 1 of these cards since they can just wait and try again.
the creature loses its skill like "ability" or status like "condition"
2 different things i think..
maybe it should have a percentage it will lose it's skiil/status
maybe 50-65 %
"Skill" is the word used by lobotomizer/illithid. Since it's the same effect the wording should match.
A percentage trigger is a possibility seems like it would be more of a flavor thing since it's a permanent, all-or-nothing effect. If the idea was reworked into an entropy card that might make sense. I'm not a huge fan of random effects otherwise though.