Open Power Auras Classic and click on the import button, Paste this string in:

Code:
Version:st3.0.0F; gcd:bofalse; b:nu1; anim1:nu1; g:nu1; optunitn:bofalse; ignoremaj:botrue; Instance25ManHeroic:nu0; stacksLower:nu0; target:bofalse; icon:stInterface\Icons\Spell_Holy_CrusaderAura; size:nu0.75; torsion:nu1; r:nu1; Instance5ManHeroic:nu0; y:nu-30; x:nu0; customname:st; groupany:botrue; isAlive:botrue; timerduration:nu0; unitn:st; bufftype:nu1; stacks:nu0; focus:bofalse; Instance10ManHeroic:nu0; raid:bofalse; texture:nu1; alpha:nu0.75; aurastext:st; InstanceBg:nu0; symetrie:nu0; owntex:bofalse; isResting:nu0; duration:nu0; mine:bofalse; stance:nu10; multiids:st; InactiveDueToState:bofalse; inVehicle:nu0; speed:nu1; Instance5Man:nu0; anim2:nu0; stacksOperator:st>=; realaura:nu1; spec1:botrue; threshold:nu50; exact:bofalse; id:nu4; HideRequest:bofalse; textaura:bofalse; Active:bofalse; buffname:stCrusader Aura; wowtex:bofalse; groupOrSelf:bofalse; customsound:st; combat:nu0; inRaid:nu0; InstanceArena:nu0; inParty:nu0; tooltipCheck:st; GTFO:nu0; aurastextfont:nu1; spec2:botrue; Instance10Man:nu0; customtex:bofalse; PvP:nu0; Instance25Man:nu0; isSecondary:bofalse; thresholdinvert:bofalse; Debug:bofalse; beginSpin:bofalse; Showing:bofalse; UseOldAnimations:bofalse; begin:nu0; off:bofalse; party:bofalse; texmode:nu1; inverse:bofalse; ismounted:nu0; targetfriend:bofalse; randomcolor:bofalse; sound:nu0; finish:nu1
Adjust your texture if you like, but this will show a texture only when the current player has the Crusader Aura Buff. Remebmer you can control + click on the PAC button in the main window and it will give you a reason why / why not the aura is being shown / not being shown. Sometimes you have to click this to get the addon to update and refresh your buffs.