、。
As an aside, this pyrogenic power is apparently called pyrokinesis.
Literal
Aside-is-but, this thought-ignition ability [genitive-の] thing [object-を] pyrokinesis [quotative-と] say [seems-らしい].
A parenthetical explanation typical of fiction/anime vocabulary-dumps. 余談だが ('as an aside,' 'this is a digression but') is a standard opener for a brief digression. 念発火能力 is the Japanese term for 'pyrokinesis' — a coined compound: 念 (thought) + 発火 (ignition) + 能力 (ability), a classic Sino-Japanese calque of a technical/fantasy concept. The construction ~のことを~という ('to call X Y,' literally 'X's matter, one says as Y') is the standard way to introduce a term for a concept: 'the phenomenon of X is called Y.' ~らしい at the end marks the naming as hearsay ('apparently'), keeping the speaker at a small distance from the claim.