I may get reamed for this but thats ok but im going with supes in both senerios. I just think that lanterns spend most their time on the defensive against someone like supes. ANd as far as energy attacks go, supes is highly resistant against them anyhow.
Gender: Male Location: Stuck In the future where Akus evil
1: yat never did anything very amazing(by ION standards) but the pure nature of his ion power mixed with his superman like ability's SHOULD be more then superman can handle.
2: supes with a blue ring would be interesting but blue massively charges green in close vicinity but supes very well could reach into yats mind and make him not fight by praying on his hopes
2. the blue rings would increase Yat power..assuming Supes can use it properly..Supes with a blue ring is > Yat with a green ring since blue > green..but Yat has Ion..i'm gonna say Yat for a small majority..