half cold, half hot
The truth is, Todoroki's power is actually that of
sharing his quirk, Half Cold, Half Hot.
When sharing his quirk, this allows for the user to generate and manipulate both ice and fire. Much like with Shouto, their right side has control over the ice, and the left side has control over the fire. This can range from minor tricks like ice crystals and cooling effects, or embers and sparks and a warming effect, to an almost armor-like effect with both elements, all the way up to colossal glaciers of ice as attacks/defense or overwhelming but (mostly) controlled wildfires.
Major emphasis should be put on
controlled, because it'd be very easy for someone inexperienced with this quirk to lose control. It's also of major note that their body temperature must be regulated - which Shouto can help with because of his vessel form and ability to use his quirk regardless of form - but most importantly, emotions can also intensify or even weaken his powers, and this goes for both god and shinki.
Also, if clothing isn't fire resistant, it
will be destroyed.