Heat Chain(赤熱鎖Hīto Chēn, lit. Red Hot Chain) is an attack of Hallie Tribeca by charging Red Hawk with fire and elongating it at high speed. It can also be used to bind the opponents.
The official spell classification is not known, despite it is more close to magic-enhanced attacks (under the Belkan magic system or with Midchildan Armed Devices). As commented by Miura Rinaldi, its attack pattern is similar to Signum's connected blades, i.e. Laevatein's Schlangeform.