The problem is with the brackets not the message function...
function servercmdwarrior(%client){
%client.player.tool[4] = nametoID(SwordItem);
messageClient(%client, 'MsgItemPickup', '', 4, nametoID(SwordItem));} //Ends function
bottomPrintAll("\c2" @ %client.name @ " \c6 has became a WARRIOR!",25,3); //Bottomprints nonexistant players
Try this:
function servercmdwarrior(%client){
%client.player.tool[4] = nametoID(SwordItem);
messageClient(%client, 'MsgItemPickup', '', 4, nametoID(SwordItem));
bottomPrintAll("\c2" @ %client.name @ " \c6 has became a WARRIOR!",25,3);}