Card Concepts That Do Not Need Repeated.

[OldTrees]

I would say untargetable is pretty dumb, and there honestly needs to be more ways to deal with such creatures.

Why is it "pretty dumb"? It is a simple consistent concept with direct counters (Shields) and a variety of indirect counters (Denial, Healing, Rush).
That said, there is no reason not to suggest more cards that directly or indirectly counter Immaterial/Burrow.

[Exeneva]

I believe it's dumb because it's simply not fun. To some extent, it's fun for the player using an untargetable creature, but for the sake of the game, permanent untargetable isn't really exciting.

I'm not saying there aren't ways to deal with it, but the ways that do deal with it are pretty direct and not really fun. Say one of your creatures is about to die. Would it be more fun if you had a spell card that prevented it from taking damage this turn, or a spell card that took the creature off the field and put it back on the next turn? Obviously, the latter is much more exciting and is more useful.

[OldTrees]

I believe it's dumb because it's simply not fun. To some extent, it's fun for the player using an untargetable creature, but for the sake of the game, permanent untargetable isn't really exciting.

I'm not saying there aren't ways to deal with it, but the ways that do deal with it are pretty direct and not really fun. Say one of your creatures is about to die. Would it be more fun if you had a spell card that prevented it from taking damage this turn, or a spell card that took the creature off the field and put it back on the next turn? Obviously, the latter is much more exciting and is more useful.

While encountering an obstacle is not fun (encountering the unknown is for some), most types of fun originate from contesting obstacles with the possibility of conquering them.

Have you tried Denial as an indirect way to counter immateriality? How about Immolation Rush?

Preventing damage for a turn could be interesting. You might want to search to see if anyone else has made a card idea off that. If they haven't then maybe you should? (PS: The latter prevents the creature from attacking. It may or may not be more useful)

[Exeneva]

What I'm saying is the latter is more fun. Sure, preventing a creature from taking damage may be more useful in this instance, that doesn't mean it's more fun or more enjoyable.

In fact, any card effect that is very direct or specific often has limited flexibility and becomes less fun to use.

[moomoose]

mono reusable death triggers, many cards have been suggested for this purpose, getting to various levels.

bringing back or making use of previously destroyed/ killed cards,  zanz is aware of the mechanic and does not want it at this juncture.

[OdinVanguard]

Shields do work for some immaterials, but  momentum + immaterial is at the very least quite annoying. Although with SoSa now its not quite as bad.

[OldTrees]

Shields do work for some immaterials, but  momentum + immaterial is at the very least quite annoying. Although with SoSa now its not quite as bad.

Quint + Momentum + Creature is a 3 card 2-3 element combo. It should not be considered annoying if you remember to count the resources they invested to protect that 1 attacker. Resources that could have been used to become a bigger threat.

[Daguerreo]

Stealing/Copying creature abilities (at least 2 in forge).
Magic gravity pull or "this creature is the only targettable".
Freezing theme