Yeah, but Dead Spike is mostly only used to end a block string or RARELY as an anti-wake up. You never just can throw it out, at any time really.
The only other thing that really kind of cripples Ragna from what i've seen is that he really can only approach from the ground (Via Hell's Fang mostly, or if you're desperate Gauntlet Hades. Carnage Scissor closes distance, but do you really want to waste 50% tension for that?), he doesn't have many effective air-to-ground moves from what i've seen other than j.C.
He is however INSANE at air combos, he can link near any of his specials into a ground combo and then link that into an air combo. It's crazy.
Yeah...i'm going to be having alot of fun playing as Ragna and learning all of those combos.