+Cavalry, +Master (2)
When Cavalry Drillmaster enters, target creature gets +2/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)
Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
Other creatures you control with flanking have flanking. (Each instance of flanking triggers separately.)
Gatherer works better in the Companion app!