When you take the Attack action on your turn, you can replace one of the attacks with a casting of one of your Sorcerer cantrips that has a casting time of an action.
Arcane Strike
Raw data
{
"name": "Arcane Strike",
"level": 6,
"__prop": "subclassFeature",
"header": 2,
"source": "ValdaSpire24Extras",
"entries": [
"When you take the {@action Attack|XPHB} action on your turn, you can replace one of the attacks with a casting of one of your {@filter Sorcerer cantrips that has a casting time of an action|spells|level=0|subclass=vagabond: mage brand (vss'24+)|cast time=action}."
],
"className": "Vagabond",
"classSource": "ValdaSpire24Extras",
"subclassSource": "ValdaSpire24Extras",
"subclassShortName": "Mage Brand"
}