Can Lissandra be used as a support

Well pretty much anyone 'can' support, it's just not always a good idea, or other champs can do it better.

Her non-ult cc is pretty short range so strikes me as somewhat unreliable, and her poke is also somewhat short ranged compared to many alternatives. I also don't know how her base damages stack up. She just has the one mobility move, so if she uses it to go in, then she's going to have trouble getting out, and if she uses to get out, then her adc is kinda left on her own.

Why would you want her over someone like malz or a more traditional support, who have more reliable stuns and similarly powerful ults?

I was thinking this myself, but she's got hella mana problems and her range is too short for how squishy she is. It's not a fun experience. I mean, go for it you want, her ult is godly, but she's not gonna be a very good pick unfortunately.

It would seem like she's just a worse version of Malz as a support. Her ult doesn't last as long as his, and she doesn't have as much damage without items.

lissandra has no mana

its not ideal... ive seen it... i have had it as my support didnt go well...

i laned against it and my adc wasnt too great about positioning and she was able to use her E to get to him and kill him and snowball and able to build lot of damage early. it was effective for her that way that game

there are just better options out there.

problem is with can be rushed as an adc in lane and it can block your ult and if they knew you support nullifies your ult and a support getting as well or as i played support vs her i took morgana and used spell shield alot to save teammates vs her ult