Name:Trueheart Twins
ManaCost:4 R
Types:Creature Jackal Warrior
PT:4/4
K:You may exert CARDNAME as it attacks.
T:Mode$ Exerted | ValidCard$ Creature.YouCtrl | Execute$ TrigPumpAll | TriggerZones$ Battlefield | TriggerDescription$ Whenever you exert a creature, creatures you control get +1/+0 until end of turn.
// This code presumes that you are only ever allowed to exert creatures you control. If this is changed in the future, it will need an update.
SVar:TrigPumpAll:AB$ PumpAll | Cost$ 0 | ValidCards$ Creature.YouCtrl | NumAtt$ +1
Oracle:You may exert Trueheart Twins as it attacks. (It won't untap during your next untap step.)\nWhenever you exert a creature, creatures you control get +1/+0 until end of turn.