Alter Echo help

Ok, i've beat the giant "Venus Flytrap of Doom" and am now up to Paavo. I have to switch between the 3 forms and use my blocks. After that, i switch to gun mode and shoot him. The bullets just tink off, but he cries "What? How is that even possible!?". His health NEVER falls. I need help. Plz?Sorry to double post, but i got him. I had to alter time to get him. Then at the end, just as you're about to finish the last one, he stops you, then you gotta fight him, like his clones. But he's really there. After you finish him, you can finish the thing. Nevin goes psycho on him. It's awesome.