Psionic constructs are a relatively new comic term. Essentially they are physical manifestations of mental powers. The best known psi-construct was the telepathic psi-knife (and later telekinetic psi-katana) of Psylocke. And her body-swapped double Revanche had a psionic sword. Later, Cable gained a psimitar ( a psionic energy spear) and Jean Grey (after she assumed the codename Phoenix) developed the power to manifest a psionic firebird ( a sparkly pink version of the Phoenix Force effect). And most recently Kid Omega manifested a psionic shotgun. Also some characters mental powers ONLY manifest as constructs, Bunker of the Teen Titans projects his psychokinetic energy as bricks, and Fixx of X-Factor has some telepathic talents that manifest as fairies. The psi-contructs aren't limited to heroes, the Black Queen of London's Hellfire Club can generate psychic skinning blades on mental chains.