Originally Posted by The5lacker
Counter to "Major Flaw 1" - Cho'Gath, Mundo, Gangplank, Nasus, Nunu, Olaf, Rumble, Singed, Sion, Skarner, Taric, Trundle, Udyr, and Yorick ALL LACK GAP CLOSERS. In addition, as a MAGE, most of Crucius's damage is likely to be from his skills.
Counter to "Major Flaw 2" Given his Ult is the only thing that costs health, and give him CRAZY good sustain, AND that his E gives him sustain, I'd say your point is pretty invalid. In addition, you could just, I don't know, build him somewhat tanky. Slap a Warmogs on him. Or a Frozen Mallet. No one is tanky enough as a default to use something like his Ult for prolonged periods of time anyways, and given his nature as a close quarters mage, NOT building him tanky is just stupid.
Counter to "Major Flaw 3" Ult is designed to be a high risk, high reward ability that allows him to engage at melee range and cause major damage, while granting him the ability to sustain. Yes, it does quite a bit. It also costs quite a bit and takes skill to maintain max use, I.E. getting within range to hit with his Q and keep as many people locked onto his E as possible to keep up the sustain. Really, it does about as much as Singed's Insanity Potion.
In regards to your other comments, Alistar has a 1 second knockup followed by a .5 second stun. That's functionally a 1.5 second stun that can't really be reduced by CC Reduction, AND deals a fairly decent chunk of damage. And in regards to your Sion comparison, again, Sion's Ult not only doesn't cost Health, but lasts for 20 seconds and heals nearby allies. 20 seconds of insane sustain and healing. Crucius's Ult is basically a combination of Sion's and Singed's, only he loses the AP, Armor and MR, Regen, and CC reduction of Singed's, and the team healing of Sion's. What he gets, however, is something more akin to Swain's Ult, wherein he triggers it when necessary, but has to watch it closely.