Developments are too complicated. They shouldn't have abilities that affect the developed land and static/triggered abilities of their own. Auras and Equipment never have standalone abilities more complicated than sacrificing them or attaching them to things. Keep in mind they have a minimum of two lines of text already.
The activated ability is unprintable. Being able to Wit's End an opponent during their draw step every turn for four mana is absurd. The restriction doesn't work because you could say you have four copies in hand and activate it twice a turn if you really wanted to.
The static ability is overpowered and boring at the same time. If you cast this when they have less than 10 power on the board, you've essentially won the game, especially since removal is off the table once it's in play. If you wanted to make this printable, I'd soften up the draw/spell locks a little, and incorporate the discard ability as something a little more workable...
Also "The Unspeakable" Is Taken6BBUU
Legendary Creature - Demon Horror (M)
When ~ enters the battlefield, if you cast it from your hand, each opponent discards his or her hand.
Whenever an opponent casts a spell, counter that spell unless its controller pays 3.
Whenever an opponent draws a card, that player discards a card unless he or she plays 3.
10/10
Making the soft locks only apply to the opponent makes them a lot better, but let's be honest, it's a 10-mana legendary mythic rare.
The problem with both versions of Rifts is that they have a huge, complex set of rules that apply to an entire type, when the rules regarding types should be the simplest things to understand. The type with the most rules is probably creature, with power, toughness, attacking, blocking, and summoning sickness. If a type, the most basic possible denomination among cards, has more rules tied to it than creatures, there's something wrong.
Can you imagine the reminder text that would have to appear on a Rift? It makes it pretty much impossible to print one at common or uncommon. Tribal cards could be printed at all rarities because they didn't require any reminder text whatsoever. It's a non-creature card with a creature type. Most people at first glance would even think it's a supertype. Planeswalkers are more complicated, but they started out only rare and got even rarer, so there's a really good chance a kid who cracks open a Garruk Wildspeaker in his Lorwyn pack will also have gotten one of those little rules cards that explains how he works. Even if Rifts are constrained to rare and above, can you imagine fitting all the rules on one of those cards? Planeswalkers are relatively simple. "These guys come into play with this many loyalty counters. You add or remove them to play their abilities once a turn during your main phase. They can be attacked and noncombat damage to you can be redirected to them, and damage makes them lose loyalty counters. Also legend rule, but with subtypes." That's pretty much every rule relevant to Planeswalkers in less than half the text of both versions of Rift.
If you're going to introduce a new type, it should be flavorful, but as you've demonstrated, anything can be justified as flavorful. It has to be simple and flavorful. If it's going to be even half as complex as Rifts, it shouldn't be a type at all, because types are by their nature simple things.
The static ability is overpowered and boring at the same time. If you cast this when they have less than 10 power on the board, you've essentially won the game, especially since removal is off the table once it's in play. If you wanted to make this printable, I'd soften up the draw/spell locks a little, and incorporate the discard ability as something a little more workable...
Also "The Unspeakable" Is Taken 6BBUU
Legendary Creature - Demon Horror (M)
When ~ enters the battlefield, if you cast it from your hand, each opponent discards his or her hand.
Whenever an opponent casts a spell, counter that spell unless its controller pays 3.
Whenever an opponent draws a card, that player discards a card unless he or she plays 3.
10/10
Making the soft locks only apply to the opponent makes them a lot better, but let's be honest, it's a 10-mana legendary mythic rare.
Can you imagine the reminder text that would have to appear on a Rift? It makes it pretty much impossible to print one at common or uncommon. Tribal cards could be printed at all rarities because they didn't require any reminder text whatsoever. It's a non-creature card with a creature type. Most people at first glance would even think it's a supertype. Planeswalkers are more complicated, but they started out only rare and got even rarer, so there's a really good chance a kid who cracks open a Garruk Wildspeaker in his Lorwyn pack will also have gotten one of those little rules cards that explains how he works. Even if Rifts are constrained to rare and above, can you imagine fitting all the rules on one of those cards? Planeswalkers are relatively simple. "These guys come into play with this many loyalty counters. You add or remove them to play their abilities once a turn during your main phase. They can be attacked and noncombat damage to you can be redirected to them, and damage makes them lose loyalty counters. Also legend rule, but with subtypes." That's pretty much every rule relevant to Planeswalkers in less than half the text of both versions of Rift.
If you're going to introduce a new type, it should be flavorful, but as you've demonstrated, anything can be justified as flavorful. It has to be simple and flavorful. If it's going to be even half as complex as Rifts, it shouldn't be a type at all, because types are by their nature simple things.