There are a few things in common between Machina Fortress, Master Hyperion and Grapha. Easy special summon, high atk and free destruction effect. Today I want to establish a good comparison between them.
Machina Fortress lv7 = 2500/1600
"You can discard Machine-Type monster(s) whose total Levels equal 8 or more to Special Summon this card from your hand or Graveyard." This part means that you can summon this monster almost at any point of the game, just like Grapha, however you probably will have to spend two or more cards to bring him from the grave (-1). While Grapha means an instant +1 in your game. The best part of the effect is the hand or grave thing, the surprise factor is amazing and it is something that grapha don't have. If grapha is in the grave and DW is on the field, is clear what is going to happen. The surprise factor is present in Master hyperion too, However Hyperion can only be summon it once by his own effect and It must be from the hand. So, you can not abuse of him like Fortress or Grapha.
"When this card is destroyed by battle and sent to the Graveyard, select and destroy 1 card your opponent controls." A free destruction effect is always great, however this one is not actually free. You have to die in battle, which means you probably will waste the effect on destroy the other battle monster. The advantage here is that Fortress has surprise factor and a easy special summon ability, which means that you can pontentially destroy 1 card on the field without your opponent be prepare for that at any point of the game. Master hyperion has a better destruction effect, because you only need to remove a fairy, but also because you can do it again the next turn. The problem here is that hyperion can not come back from the grave easily, so if you waste hyperion, you probably won't be able to destroy anything until you get the next hyperion. This problem becomes bigger if we think about Grapha, in fact you can't summon grapha without waste his destruction effect, of course you always have something to destroy... or not?
"When this face-up card you control is targeted by an opponent's Effect Monster's effect, look at your opponent's hand and discard 1 card from their hand." This is something exclusive of Fortress, is a backup effect in case your opponent is trying to get rid of Fortress easily. Great effect but ironically is bad against Dark world.
His 1600 def means that it can be destroyed by tengu. At this point, fortress could be an old fashion boss monster.
Master Hyperion lv8= 2700/2100
"You can Special Summon this card from your hand by removing from play 1 "The Agent" monster in your hand, field, or Graveyard." Totally easy to summon, and the surprise factor is huge, but it can not come back from the grave like Fortress or grapha. When you summon this card, it create any mathematical change on the game like Fortress (-1) or grapha (+1). However the free destruction effect can create an instant +1 for you. His attack is enough to make it a game changer card.
"Once per turn, you can remove from play 1 LIGHT Fairy-Type monster from your Graveyard to select 1 card on the field, and destroy it." Everybody read this effects and think on DAD, and it is true, is just like DAD, however it can only destroy one each turn, and it can not be splashed on any deck like DAD.
His 2100 def means that it can not be destroyed by tengu, but also can not be destroyed by any GK monster. This makes hyperon more prepare for the meta.
Grapha, Dragon lord of Dark World lv8= 2700/1800
"You can Special Summon this card (from your Graveyard) by returning 1 face-up "Dark World" monster you control to the hand, except "Grapha, Dragon Lord of Dark World"." Totally predictable summon, also, you expose one card of your hand, so your opponent can see what is coming next. In the future, this will become the easiest deck to beat. The main advantage of Grapha is that it is a (+1) 3000 atk floater, something probably unbeatable on battle on this game... ever. This is something that Hyperion or Fortress can not score.
"If this card is discarded to the Graveyard by a card effect: Target 1 card your opponent controls; destroy that target, then, if this card was discarded from your hand to your Graveyard by an opponent's card effect, look at 1 random card in your opponent's hand, then, if it was a monster, you can Special Summon it to your side of the field." Yes, a free destruction effect was never so easy on this game. However, it also means that you have to use it before put grapha on the field. What if your opponent don't compromise any card on the field? Are you willing to waste Grapha effect? Of course you are, because right now the deck has enough +1 to make those kinds of sacrifice, but it won't be capable of do it on the future, and it will be his major weakness. 
