Not that I know of. I'm pretty sure you can only convert into minions, or to another team.
Why not give a unit a lightning attack? Thats a cool attack... especially with Petchusos'(crocodile guy) beam projectile used. And if you give that beam projectile to an archer unit(say Odysseus), then they'll shoot a little yellow shard. It looks neat...
(You can ignore my ramblings)
~The Grandest Admiral~
"Toss me."
"What?"
"I cannot jump the distance so you'll have to toss me. Ehh.. Don’t tell the elf."
"Not a word."
~Still a Member of DFD Masters~