Other creatures you control with flanking have flanking. That second line seems redundant and sounds a bit silly when read aloud
However, Training Grounds and Biomancer's Familiar can make things a lot less expensive and turn Eulogist into a lean, Green, graveyard-tilling machine that pulls a Karador deck's pants down while churning out an army of clones that would make those creepy tall aliens on Kamino envious
You can still declare the creature as a blocker just like any other
There have definitely been games that I could have won earlier if I had a cheap haste enabler online
(Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.) At the beginning of combat on your turn, if you have a full party, creatures you control get +1/+0 and gain indestructible until end of turn
Other landfall abilities that generate tokens, like Felidar Retreats, can also help you build a bigger board state while ramping